PTPRC and neoplasm: By contrast, anti-4-1BB minimally affected the tumor infiltration of other main immune cell subsets including B cells (B220+), myeloid-derived suppressor cells (MDSCs, Gr1+CD11b+), dendritic cells (DC, CD11b+CD11c+Gr1−), and NK cells (NK1.1+) (Fig. 1e).