CSF1R and neoplasm: In the mouse mammary tumor virus‐driven polyomavirus middle T antigen (MMTV‐PyMT) model of mammary carcinogenesis, using BLZ945, a small molecule inhibitor of CSF1R, significantly decreased the number of macrophages and increased the number of CD8+ T cells in tumor tissues, leading to attenuate the growth of the primary mammary tumor.86