For physical ICD inducers [47], RT delivered according to a hypofractionated schedule to a single neoplastic lesion has been demonstrated to synergize with CTLA4 and/or PD-1 blockers in immunocompetent BALB/c mice bearing bilateral TS/A mammary carcinomas or 344SQ lung carcinomas s.c., ultimately resulting in (at least some degree of) control of the contralateral, nonirradiated lesion [48–51], as well as in wild-type BALB/c mice with subcutaneous 4T1 mammary carcinomas, culminating with partial control of metastatic lung nodules [52]. Here, CTLA4 is linked to breast carcinoma.