U2AF1 and intrahepatic cholangiocarcinoma: Therefore, the second step of the ICC relies almost entirely on NGS for both identification and quantification of TP53 mutations and for detecting mutations in ASXL1, BCOR, EZH2, SF3B1, SRSF2, STAG2, U2AF1, ZRSR2, and RUNX1, which are myelodysplasia-related genes [57].