Adoptive transfers of TAM subsets. For the adoptive transfer experiments, 2 × 106 sorted F4/80+MHC IIhi and F4/80+MHC IIlow cells derived from tumors on Day 21 after inoculation (n = 20) were injected into the tumor tissues of other mice 2 days after tumor inoculation (n = 4). PBS was used as the control. (A) Tumor size. (B) Tumor weight. (C) MHC class II expression in the differently treated tumors was examined by immunostaining and counting (n = 4) (× 400 magnification). The bars represent the mean ± SD; *p < 0.05, **p < 0.01, ***p < 0.001 (unpaired Student's t-test).