JAK1 and pachyonychia congenita: Furthermore, Tam et al. studied the expression levels STAT pathway in the transition from a hormone-sensitive to hormone-refractory PC by assessing the expression levels of these IL-6R, JAK1, STAT3, pSTAT3 (Y705), and pSTAT3-Ser727 (S727) by IHC in 50 matched hormone-sensitive and hormone-refractory tumors pairs.