A new review from the FDA says it finds no evidence linking the two, but that research should continue.

The findings: The report reviewed 125 experiments carried out on animals and 75 on humans between 2008 and August 2019. In summary, the FDA said that there’s “no consistent pattern” to link radiofrequency radiation, or RFR, to tumors or cancer.

Rats don’t use cell phones the way humans do. An overarching problem with the animal studies in the review is that they don’t mimic how humans actually use their phones. Animal studies often douse a rat’s entire body in radiation at levels that are far higher than what humans are normally exposed to when we use cell phones. The human studies were also flawed, relying only on questionnaires from family members or observational data.

What does this mean for 5G? 5G works at much higher frequencies than 4G, sparking fears that it could cause tumors or cancer and prompting protests in California and across the European Union. In a note to accompany the report, the FDA said it was important to understand the health effects of cell phones in a world moving toward 5G. The technology falls within current FCC exposure guidelines, which say that humans can safely be exposed to radiation between 300 kilohertz and 100 gigahertz. (5G currently spans the range between 25.250 GHz and less than 100 GHz.)

More research needed: The FCC has repeatedly insisted that 5G is safe, and this report concurs: “Existing epidemiological evidence indicates that if any risk does exist, it is extremely low compared to both the natural incidence of the disease and known controllable risk factors.” That said, the FDA urged researchers to continue studying the effects of cell phones on humans, particularly those predisposed to tumors.