KLRK1 and breast cancer: Among the types from both FUSCC and Lehmann’s subtyping systems, immunomodulatory (IM) TNBC featured more activated NK cells, which was consistent with previous studies, proving IM being more inflammatory than other subtypes [16, 34].The NK cell activation markers, CD69, KLRB1, KLRK1 and FCGR3A were downregulated in ER+BC (Fig. 1C1, C2) [35].