TP53 and cholangiocarcinoma: Taking into account all of the alterations mentioned above, Jusakul et al. divided CCA into four clinically significant clusters: fluke-positive CCAs (clusters 1/2) characterised by ERBB2 amplifications and TP53 mutations; fluke-negative CCAs (clusters 3/4) with PD-1/PD-L2 expression; epigenetic mutations; and FGFR gene rearrangements [58].