The results indicated that the concentrations of 20 cytokines (IFN-α2, IL-17F, IL-23, IL-27, IP-10, I-TAC, TSLP, MCP-1α, GM-CSF, IL-1α, IL-1β, IL-4, IL-5, IL-6, IL-8, IL-9, IL-10, IL-12p40, IL-13 and IL-17A) in B-CS patients were significantly increased as compared to control populations (P < 0.001) (Fig. 3A). Here, IL9 is linked to Cowden syndrome 1.