JAK1 and pY-STAT3 knockdown blocks tumor cell–induced repression of FLG and FLG2 in the epidermis. NHEK cells were transfected with siRNA targeting either JAK1, JAK2, or STAT3 or a nontargeting siRNA control. After 48 hours, the samples were cultured for 24 hours with the supernatant from the malignant MF2059 T-cell line. The mRNA expression was analyzed by qPCR using β-actin as a reference gene. Gene expression was given as relative expressions. (A) mRNA expression of FLG, FLG-2, and JAK1 was analyzed following siRNA-mediated knockdown of JAK1 in the presence or absence of supernatant from MF2059. mRNA expression of FLG, FLG2, and JAK2 (B) or STAT3 (C) was analyzed following siRNA-mediated knockdown of JAK2 (B) or STAT3 (C) in the presence or absence of supernatant from MF2059. n = 3, ∗P < .05. NT, nontargeting; sup, supernatant.