MICA/B protein was rarely detected in the normal breast tissues of BC patients (84.4% showed negative MICA/B expression). However, in BC tissues, 92.2% showed positive MICA/B expression (Figures 1a and b). The MICA/B mRNA expression level was detected less in normal breast tissues than in paired BC tissues (Supplementary Figure 1a). Together, these results showed that the expression of MICA/B was higher in BC tissues than in normal breast tissues.