ENTPD1 and neoplasm: While a higher frequency of CD39SP CD8+ T cells was found in the stroma, the frequency of CD39+CD103+ cells among CD8+ T cells was equal in tumor nest and stroma and notably, the highest frequencies of CD103SP cells among CD8+ T cells were observed inside of the tumor nest (figure 3B,D) Immunofluorescence staining patterns illustrate that CD8+ T cells in the tumor nest are typically CD103+ and indeed, CD8+ T cells that did not express CD103 were restricted to the stromal area (figure 3E).