ERBB2 and breast cancer: KLRB1 expression levels correlated with tumor purity in BC (p = 2.66e−88, r =  − 0.574), as well as with luminal type (p = 2.35e−42, r =  − 0.538), HER2-enriched (p = 2.22e−05, r =  − 0.522), and basal-like (p = 2.39e−17, r =  − 0.658) BC.