Although the decrease in percentages of proliferating immune cells (all four immune subpopulations) at day 15 was consistently observed across all subgroups, a statistically significant increase in immune cells density (all four immune subpopulations) at day 15 was only observed in HR-negative and HER2-enriched subtype (all P values < 0.05 except for CD4+in HER2-enriched tumours P = 0.055), but not in HR-positive and non-HER2-enriched PAM50 subtypes. Here, CD4 is linked to neoplasm.