As displayed in Supplementary Figure 7, the genes enriched in the PI3K signaling pathway in Ubenimex-treated MKN-45/DDP cells included PIK3R1, AKT1, NFKBIA, RELA, etc. Consistently, Ubenimex markedly reduced the total amount of PI3K (P85) and phospho-PI3K (p-P85), as well as endogenous AKT and phospho-AKT in CDDP-resistant GC cells (Figure 6D–6F). This evidence concerns the gene PIK3R1 and gastric cancer.