Also in ER+ breast cancer, atypical chemokine receptor (ACKR1)+ endothelial cells (ECs) had 15-fold increased homotypic interaction probabilities and more predicted interactions with several cell populations in the younger cohort (Fig. 5j), aligning with their enhanced protein secretion and metabolic activity ARPs in younger patients (Fig. 3c). This evidence concerns the gene ACKR1 and breast carcinoma.