The association of BIRC2 mRNA expression and the immunotherapeutic response. (A) The relationship between BIRC2 mRNA expression and the different immune subtypes of HCC (TISIDB). (B) The correlation between the expression of immune checkpoint genes PDCD1 (Programmed cell death protein 1, PD-1), CD274 (Programmed cell death protein 1, PD-L1), and cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) with the mRNA expression of BIRC2 in HCC tissue (BEST). (C) A comparison in the mRNA expression of BIRC2 in anti-PD-1, anti-PD-1/PD-L1, and anti-PD-1/CTLA-4 responders and nonresponders based on the Asicerto, Kim, and Riaz cohorts (BEST). (D) ROC curve of BIRC2 expression for patients in the Asicerto, Riaz, and Gao cohorts (BEST).