CYP26A1 and hepatocellular carcinoma: To explore whether the expression of angiogenesis- and ADME-related genes identified in the decision tree (i.e., SLC22A4, ADH1A, VEGF-A, VEGF-C, HIF-1α, and CYP26A1) might have a role in HCC disease outcome in terms of response to sorafenib, we carried out bioinformatic analysis of these genes using the public dataset GSE109211, downloaded from GEO, in which data from a subset of HCC patients (n = 67) treated with sorafenib are reported.