CTLA4 and cancer: Tumors achieve immune privilege through the immunoediting1, 2, 3 of themselves and the formation of an immunosuppressive TME.4, 5 The heterogeneity of TME can actively shape antitumor immunity and influence therapeutic response.6 Co‐inhibitory receptors, such as CTLA4 and PD1, have essential yet distinct7 roles in modulating immune responses and have been proven to be valid targets in cancer immunotherapy.8, 9 Moreover, the next wave of co‐inhibitory receptor targets, including LAG‐3, Tim‐3, and TIGIT,10 are being explored in clinical trials.