Table 1 demonstrates that the same signaling factors can play a role in different CIDs such as multiple sclerosis (TYK2, CD40, TNFAIP3, PTPN22, IL-2, IL-2RA and others; ref. [44]), type 1 diabetes mellitus (TNFAIP3, PTPN22, IL-2, IL-2RA, SH2B3 and others, refs. [45–47]), systemic lupus erythematosus (TYK2, TNFAIP3, PTPN22, FCGR2B, reviewed in ref. [48]), and Crohn’s disease (TYK2, PTPN22, IL-2RA, ICOSLG and others, ref. [49]). The gene discussed is IL2; the disease is type 1 diabetes mellitus.