In spite of its pronounced teratogenic activity, thalidomide raised renewed interest as an inhibitor of TNFα secretion in the 1990s [474], and was approved by the US FDA (under a strictly controlled distribution program) for the therapy of erythema nodosum leprosum (a complication of leprosy etiologically linked to TNFα) in 1998 [475]. This evidence concerns the gene TNF and leprosy.