Studies of recent interest show that the Insulin/IGF axis play an important role in aging. Nematodes, fruit-flies and other organisms have an increased life span when the gene equivalent to the mammalian insulin is knocked out. It is somewhat difficult to relate this finding to the mammal, however, because in the smaller organism there are many genes (at least 37 in the nematode) that are "insulin-like" or "IGF-1-like", whereas in the mammals insulin-like proteins comprise only 7 members (insulin, IGFs, relaxins, EPIL, and relaxin-like factor) and have apparently distinct roles with some but relatively less crosstalk.