The silence of IPMK enhanced the expression of immune checkpoint and promoted infiltration and M2 polarization of macrophages. The relative expression levels of PD-1, PD-L1, and CTLA-4 in MCF-7 (A) and MDA-MB-231 cells (B) after silencing IPMK were compared with the si-NC groups. After co-culturing THP-1 generated M0 macrophages with BC cells (C) for 48 h with Transwell plates, the expressions of M2 biomarkers (ARG1 and CD23) and M1 biomarkers (INOS and CCR27) of macrophage (D–G) were detected by qRT-PCR. Then, the macrophages were seeded in the upper chamber of Transwell plates (H). The number of migrated macrophages after co-culture for 48 h with MCF-7 (I) and MDA-MB-231 (J) were calculated by Image J. The protein expressions of IL-4 and IL-6 of MCF-7 (K) and MDA-MB-231 cells (L) were detected using western blot analysis. *P < 0.5; **P < 0.01; ***P < 0.001.