ACTA2 and cancer: Although radiotherapy provides significant benefits, long‐term fibrosis can severely impact patients’ quality of life, with fibroblasts playing a critical role.[33] We focused on cancer‐associated fibroblasts (CAFs) and identified four subtypes (Figure S3a,b, Supporting Information): myofibroblast‐like CAFs (CAF_myo, ACTA2+), adipose CAFs (CAF_adi, CFD+), inflammatory CAFs (CAF_infla, POSTIN+), and antigen‐presenting CAFs (CAF_ap, HLA‐DRA+).