SLAMF6 and breast cancer: TCF1 and SLAMF6 are both recognized as markers for progenitor-exhausted T cells8,10, and hence it would be expected that the expression of TCF7 is positively correlated with that of SLAMF6. Indeed, analysis of TCGA data demonstrated that TCF7 expression was higher in the SLAMF6 high tumors than in the SLAMF6 low tumors both in breast cancer and melanoma.