HDAC9 and colorectal cancer: The triple combination therapy, consisting of the PD-1 antibody sintilimab, the HDAC inhibitor chidamide, and the anti-VEGF antibody bevacizumab, demonstrated significant efficacy in patients with colorectal cancer of the MSS/pMMR phenotype. Notably, it substantially outperformed the double combination therapy across multiple endpoints, including progression-free survival, objective remission rate, and disease control rate.