Interestingly, the authors showed that dual administration of the two drugs decreased the expression of several genes, such as PERK, ATF4, CHOP, eIF2α, and ATF6, implicated in ER stress, and targeting ER stress enhanced the sensitivity of ESCC cells to SP2509 and G9a treatment, which provided strong supporting evidence that targeting LSD1, G9a, and ER stress could serve as a promising strategy for clinical treatment of ESCC patients [12]. Here, ATF4 is linked to esophageal squamous cell carcinoma.