Some studies suggest that MpBC expresses PD-L1 [7]. In their study, Joneja et al. identified that PD-L1 expression was detected in 46% of MpBC patients in their study (n=75), predominantly over other subtypes such as hormone-receptor positive and HER2/neu-receptor positive breast cancers [7]. The gene discussed is ERBB2; the disease is breast carcinoma.