ENTPD1 and colorectal cancer: ,2,12,26 A recent study in colorectal cancer found tumor-infiltrating MAIT cells enriched with CD4+FOXP3+CD39+ MAIT cells,46 which along with our studies during Mtb infection1 suggest specialized functions for CD4+ MAIT cells beyond a marker of early development or cytotoxicity that may be disease and tissue specific.