While Lyn protected the host against autoimmunity by inducing a constitutive phosphorylation of SHP-1Y536 residue, Fyn favored autoimmunity by inactivation of SHP-1 through the phosphorylation of the SHP-1S591 residue associated with induction of SykY525–526 phosphorylation (Fig. 6a–c). The gene discussed is FYN; the disease is Autoimmunity.