An article titled The Role and Therapeutic Targeting of CCR5 in Breast Cancer, in a journal called CELLS, reaffirms that "Over 95% of TNBC tumors expressed CCR5." And "In an analysis of >2200 breast cancer patients, >95% of triple-negative breast cancer (TNBC) were CCR5+"

I am not sure how the Histo number of 44 for TNBC in your graph is measured, but it seems hard to believe such a low comparative number for a disease where over 95% of the tumors expressed CCR5. There seems to be a dissonance there.