FZD4 and familial pancreatic carcinoma: MiR-29c down-expresses during pancreatic cancer and directly modulates WNT upstream regulators, including FRAT regulator of WNT signaling pathway 2 (FRAT2), frizzled cass receptor 5 (FZD5), lipoprotein receptor-related protein 6 (LRP-6) and frizzled class receptor 4 (FZD4).