A potential link between MTHFD2 and the immune system was already suggested in the 1985 paper by Mejia and MacKenzie who had reported the detection of the NAD+-dependent methylenetetrahydrofolate dehydrogenase activity, not only in tumour cells but also in the bone marrow, thymus, spleen, that is, organs relating to the immune system. Here, MTHFD2L is linked to neoplasm.