In breast cancer patients, fewer intratumoral and stromal CD4+ and CD8+ TILs were observed in BrM as compared to the primary tumor (Sobottka et al., 2016; Ogiya et al., 2017) or to metastatic cancer lesions at other sites (Cimino-Mathews et al., 2013). This evidence concerns the gene CD4 and breast carcinoma.