Remarkably, studies on Tyro3−/−Axl−/−Mer−/− triple mutant mice (TAM TKOs) have demonstrated that loss of function of the three receptors, Tyro3, Axl, and Mer, dysregulates the immune system, presented by a severe lymphoproliferative disorder accompanied by a broad-spectrum autoimmune disease (39, 87). This evidence concerns the gene TYRO3 and lymphoproliferative syndrome.