Among the five PD‐L1 status‐associated genes obtained from Mendel's randomized analysis in MHC‐II related genes (ANXA1, CNN2, ITGB7, MMP25, and PTMA), ANXA1 has been widely reported to be potentially associated with PD‐1/PD‐L1 resistance; therefore, we focused on analyzing the association of ANXA1 with breast cancer and its association with PD‐1/PD‐L1 resistance. This evidence concerns the gene CNN2 and breast cancer.