The association of dense infiltration in HER2+ tumours and TNBC can be best interpreted as a pro-tumorigenic function of TILs especially due to higher infiltration of Tregs.10,63 Our findings regarding the association of PD1 and PDL1 in TILs with higher tumour grade, were supported by the findings of Muenst et al.58 This association with higher grade emphasises the role of PD1/PDL1 pathway adopted by DCIS to evade anti-tumour immunity and spread aggressively. This evidence concerns the gene ERBB2 and ductal breast carcinoma in situ.