DISTANCE is not dead. In biotechnology, as in other tech-based industries, the clustering of similar firms is more important than ever. Some American biotech startups are based in the San Francisco and Silicon Valley area, huddled with its many digital and IT startups. But the Boston metropolitan area—and in particular Cambridge, across the Charles river from central Boston—seems to be holding its own as the world’s pre-eminent biotech hub.

The San Francisco area’s pool of venture capital is beyond compare; and a biotech-industry body there, the California Life Sciences Association, argues that California is the number one state for biomedical employment. But in part that is simply a reflection of the state’s large population, which means its health-care business is necessarily big. The Massachusetts Biotechnology Council claims that its state employs more people in biotech research and development than any other.

A study published last month by the Massachusetts Institute of Technology (MIT) found that although, per head, the Boston area had fallen well behind San Francisco and Silicon Valley in creating software and internet startups, it was more or less keeping pace in life sciences. The density of research institutions in Massachusetts means that it receives $351 per head in funding from the National Institutes of Health, well ahead of the Golden State’s $88. This density of research was a reason cited by General Electric, which has a big medical-technology division, in its announcement this week that it will move its group headquarters to Boston.

The history of the Boston area cluster can be traced to the late 1970s and early 1980s, when Biogen and Genzyme, two biotech drugmakers, were founded by scientists from nearby academic institutions. Other scientists, especially from MIT and Harvard, Cambridge’s two internationally renowned universities, followed suit and created innovative startups of their own.

This encouraged global pharmaceutical giants, struggling with poor productivity in their existing research facilities, to set up labs in and around Cambridge. Novartis of Switzerland began work on its outpost in 2002, followed by such names as AstraZeneca of Britain and Baxter of Illinois, which in 2015 spun out its Cambridge labs as Baxalta, a specialist in “orphan” diseases. This week Baxalta agreed a $32 billion takeover by Shire, an Irish drugs giant.

The cluster lacked a clear focal point until 2010, when MIT, the main landowner around Kendall Square—an area about a mile in all directions from the Kendall/MIT subway station in Cambridge—decided to spruce it up. One report suggests the square currently hosts firms that have absorbed about $14 billion in venture-capital investments. Silicon Valley’s overall pool of capital may be deeper, but much of it flows to areas other than biotech. And the global drug giants with outposts in the Boston area provide an alternative source of finance, and of eventual buyers for startups.

Tom Andrews of Alexandria Real Estate, a property agent specialising in science buildings, notes that the Boston area’s universities, teaching hospitals and other institutions are a sink, as well as a source, of talent. Anyone who accepts a risky job at a startup can be sure that if things don’t work out there are lots of big employers nearby to fall back on.

The cluster’s promising young firms include four—Editas Medicine, CRISPR Therapeutics, Intellia and Bluebird Bio—that are working on “gene editing”, currently one of the hottest areas of biotech. WuXi NextCODE, another local startup, specialises in analysing genomes. Alnylam concentrates on drugs that interfere with RNA, the messenger molecule through which genes express themselves. Not satisfied with just editing, deciphering or blocking nature’s blueprints, Synlogic is seeking to create medicines through entirely artificial sequences of genes.

Synlogic’s boss, Jose-Carlos Gutiérrez-Ramos, formerly of Pfizer, has worked around the world and praises the “density of intellectuals” in Boston and the opportunities that come from being able to make easy connections. With little travel time between appointments, it is easier to arrange meetings. Dan Budwick of Pure Communications, a public-relations firm which represents some of the area’s startups, says that “You can jump on a bike and see 30 companies in a mile. You can’t do that in San Francisco or Manhattan.”

Boston’s tech cluster has a different vibe from Silicon Valley’s in other ways too. For some locals, beer is the recreational drug of choice, rather than cannabis. Boston’s biotech crowd are a more formal bunch, who wear proper shirts—and tuck them in. And Edward Farmer of WuXi NextCODE says that Bostonians know which fork is for the salad because salad is not the only thing they eat.

The cranes sprouting across the skyline suggest more growth ahead. But demand is still running ahead of supply. In the Boston area rents for laboratory space rose by 7% last year to around $47 a square foot ($505 a square metre), compared with $37 in San Francisco. Already, some companies are having to seek space in districts like Alewife or Watertown, on the far side of Harvard’s campus.

Though it is on a roll, the Boston biotech cluster must keep a nervous eye on its West Coast rival, especially if, in future, biotech ventures come to rely on software, wearable sensors and big-data analysis, areas in which Silicon Valley is strong. At least that is a problem it can try to address. The weather is not. The biggest annual jamboree for investors in biotech, organised by J.P. Morgan, a bank, opened this week in its customary location of San Francisco. The temperature was a balmy 13º Celsius, to Boston’s shivering -1º.

Clarification: The last-but-two paragraph of this article has been amended since publication to make it clear which comments we are attributing to Edward Farmer of WuXi NextCODE.