CTLA4 and cancer: Interestingly, HOXATs, including HOXB-AS1, HOXC-AS2, HAGLR, HOTAIR, and HOTAIRM1 showed significant positive correlation with the expression levels of immune checkpoint genes, including CTLA-4 and PD-L1, suggesting that these HOXATs are involved in the regulation of immune responses in different cancer types (Figures 4A,B).