MRC1 and neoplasm: Because CD206 is a well-defined marker representing polarization toward M2-like macrophages (67), we then examined the M1- (classically activated macrophages; CD206-, MHC IIhigh) and M2- (alternatively activated macrophages; CD206+, MHC IIlow/neg) like tumor-associated macrophages, and found a significant increase of the ratio of M1:M2 macrophages (Figures 5J), suggesting that the disruption of the acidic tumor microenvironment had compromised the recruitment and enrichment of CD206-expressing M2-like TAMs in the tumors.