KRT10 and psoriasis: 128 Enriched phenol and p-cresol suppress the expression of keratin 10 and dys-regulate the differentiation of keratinocytes as well as the skin barrier function.129 Moreover, trimethylamine N-oxide is elevated in the blood of patients with psoriasis, inducing M1-type polarization of macrophages, promoting inflammation, and increasing the risk of psoriasis comorbidities.130,131 Decreased circulatory branched-chain amino acids and vitamin B6 have also been demonstrated in patients with PSC.132