NKD2 and cholangiocarcinoma: Next, we selected several EZH2, LSD1 or DNMT1 potential targets (P15, P21, LATS2, RND1, KLF2, NKD2, PTEN) with tumor-suppressor function and SPRY4, and hypothesized that they may involve in the contributions of SPRY4-IT1 to CCA progression.