CD8A and breast cancer: In the present study, CD3 and CD8 mRNA derives solely from TILs, as no staining of CD3 or CD8 has ever been reported in breast cancer cells, whether such staining was evaluated by classic IHC48 or the AQUA method.49 As for FOXP3, a very small percentage of breast cancer cells might show weak nuclear staining, which is detectable in only 1% of breast cancer cases.50 Therefore, most if not all of the FOXP3 mRNA expression detected in our study comes from TILs, as well and not tumor cells.