FGFR4 and colorectal carcinoma: The mechanistic insights into CAF-promoted CRC proliferation are provided by other non-negligible clues, which show that the microRNA-31 (Yang et al., 2016), the long non-coding RNA UCA1 (Jahangiri et al., 2019), and some signaling pathways, including PI3K-Akt (Yamamura et al., 2015), FGF-1/-3/FGFR4 (Bai et al., 2015), HGF-MET (Wen et al., 2020), and ERK5/PD-L1 signaling axes (Zhang M. et al., 2020), also act as important modifiers mediating the pro-proliferative effects of CAFs on CRC.