TYMS and Hand-foot syndrome: The rs2612091 and rs2741171 variants, lying downstream of TYMS within an intron of enolase superfamily member 1 (ENOSF1), were significant associated with HFS, irrespective of the two TYMS polymorphisms {5′-variable number of tandem repeat (5′-VNTR) 2R/3R [36] and 3′-UTR 6 bp ins-del [43]} that have previously been reported to affect 5-FU toxicity [16].