ZDHHC9 and breast cancer: Of note, unlike ZDHHC9-mediated PD-L1 palmitoylation in breast cancer cells, palmitoylation of PD-L1 in colorectal cancer cells is mediated by ZDHHC3 but not ZDHHC9, indicating that PD-L1 utilizes multiple ZDHHCs to ensure its palmitoylation in different contexts.