If you’ve ever gone in to donate blood, you’ll be familiar with the question: What type are you?

It’s something most of us rarely think about, an invisible part of our biology. And yet, it determines a great deal about how we function and what will happen to us if we need a transfusion one day. Quietly, our blood also determines many risk factors for our overall wellbeing. Yet, more than a century after Austrian physician Karl Landsteiner first identified typed blood, we are still uncertain of why the feature developed.

However, blood has had a long and convoluted history for something that is such an integral part of how our bodies work. Very few animals can live without some form of blood — cephalopods such as octopi have copper-based hemocyanin, which is green, and other organisms have hemolymph, a type of circulatory fluid, which is blue. (Ironically, insects have blue blood, so the term blueblood is more likely to refer to an insect prince than a human nobleman.) Ours is known as hemoglobin and is iron-based, making it red.

On each of the erythrocytes, or red blood cells, in our veins, there either are or are not antibodies that determines our blood type. The most important is the ABO system — cells will have an A, B or no antibody. The other is called the immunogenic D antigen and determines the “positive” or “negative” after the type, known as the Rhesus factor. Besides determining who can give us blood in transfusions, some blood types have been linked to higher incidences of certain diseases such as cancer.

The most immediate application of blood typing, however, is the ability to save the life of someone who is dying of blood loss. However, the U.S. frequently faces a blood shortage, largely due to increasing need but also because of a lack of donations. Someone needs blood every two seconds in the U.S., according to the American Red Cross, many of whom are cancer patient undergoing chemotherapy. Cancer diagnosis rates are rising and those needs are likely to increase, driving the need more more blood storage. Most hospitals and trauma centers request Type O blood, and only Type O-negative can be transfused to all patients because it has no ABO antigen or immunogenic D antigen. It is, however, often in short supply.

Researchers have been working on artificial platelets for years, but a new proposed method could circumvent it by changing the donated blood instead.

A group of researchers from Canada published a proposed method for using enzymes to strip blood of its antigens. The study, published in the Journal of the American Chemical Society, details the use of a bacteria enzyme to attach to the antigens and remove them from the erythrocyte. Interestingly, the bacteria used comes from Streptococcus pneumoniae, the bacteria that causes pneumonia. It cleanly cleaves the antigen from both sides of the cell, leaving a cell similar to Type O-negative.

This could potentially create a more neutral blood supply that could aid in disasters such as the Nepalese earthquake or in areas of overwhelming need, such as communities with high rates of sickle cell anemia. Only individuals of African descent inherit that disease, so the disparity of access tends to greatly affect that community. But overall, it means that anyone can donate at any time and know their blood will not go unused.

Blood typing can also tell an interesting story of where we come from and why. There are still so few hints as to why we have blood types and what they mean for our day to day lives, other than diseases. The method is still a proposal, in the pre-research stages, but a deeper look into what makes our blood the way it is could tell us much about our own histories.