Putative co-expression of let-7e with FADD, CASP3, Belclin-1 and LC3B. (A and B) Significant negative associations were observed between (A) let-7e and FADD in COAD and (B) let-7e and CASP3 in LUSC. (C and D) Significant positive associations were observed between (C) let-7e and Belclin-1 in COAD and (D) let-7e and LC3B in LIHC. COAD, colon adenocarcinoma; LUSC, lung squamous cell carcinoma; LIHC, liver hepatocellular carcinoma; FADD, FAS-associated death domain; CASP3, caspase-3; LC3B, microtubule-associated protein 1 light chain 3 β.