MSR1 and neoplasm: Furthermore, a number of markers of alternatively activated or 'M2' genes were expressed at higher levels within the tumor tissue compared with NAT such as cd163, mrc1, msr1 whereas there were similar levels of PD-L1 (cd274) expression in the TME and NAT provided evidence that the TME harbors 'M2' or tumor-promoting macrophages (Fig. 4C).