HCAR2 and psoriasis: The data so far demonstrated the consequences of HCA2-deficiency several-fold: (i) the psoriasis-like inflammation response to IMQ is remarkably enhanced; (ii) Treg may switch from a regulatory into a proinflammatory type; (iii) IL-6 expression is enhanced; (iv) the skin microbiome is altered, which appears to be the most upstream phenomenon in this cascade (Figure 8).