Notably, 18 of the 20 downregulated DE-TrpGs (ALDH9A1, ALDH3A2, ADH1B, AOX1, MAOA, ECHS1, ALDH2, ACAT1, HAAO, ALDH7A1, HADHA, AKR1A1, CYP4X1, INMT, CYP2U1, CAT, HADH, and NMNAT1) showed significantly reduced expression specifically in ESCC fibroblasts compared to their normal counterparts. This evidence concerns the gene HAAO and esophageal squamous cell carcinoma.