FGFR4 and oral cavity squamous cell carcinoma: Examples are FGFR4 rs351855 in HCC (Sheu et al., 2015), FGFR4 SNP rs2011077 with rs1966265 in urothelial cell carcinoma (Tsay et al., 2019), and FGFR4 rs2011077 and rs1966265 in oral squamous cell carcinoma.