OR4F3 and cholangiocarcinoma: The analysis of candidate RNA biomarkers in serum EVs from CCA vs. healthy individuals pointed out ring finger and FYVE like domain containing E3 ubiquitin protein ligase (RFFL), olfactory receptor family 4 subfamily F member 3 (OR4F3), and the family with sequence similarity 107 member B (FAM107B) as the mRNAs with the highest diagnostic capacity, presenting AUC values of 1.00, 1.00, and 0.991, respectively, along with the non-coding RNAs PMS1 homolog 2 mismatch repair system component pseudogene 4 (PMS2L4), miR-604, and SNORA58 (AUC: 0.991, 0.944, and 0.926, respectively) (Figure 3A).