CD4 and ductal breast carcinoma in situ: In HR-negative group, high infiltration of CD4+, CD8+ and FOXP3+ TILs and PD-L1+ immune cells were also associated with high HLA class I expression in both DCIS and IBC, albeit with borderline significance for CD4+ and CD8+ TIL infiltration in DCIS and CD4+ TIL infiltration in IBC.