CD4 and ductal breast carcinoma in situ: In HR-negative tumors, CD4+ TIL showed a gradual increase from pure DCIS to DCIS-M and DCIS-INV (p = 0.036, pure DCIS vs. DCIS-M; p = 0.063, DCIS-M vs. DCIS-INV; p = 0.003, pure DCIS vs. DCIS-INV).