FOXP3 and neoplasm: This hypothesis may be supported by our finding that high CD25+, FOXP3+, and CD25+FOXP3+CD45RA− stromal cell counts were all significantly associated with both high CD8+ TIC count (Fig. 3A) and MSI-high (Table 5), as MSI is known to cause high tumor mutation burden (TMB), leading to activation of antitumor immunity [33].