Bmemory expressed the memory marker CD27 together with switched isotypes IGHG1 and IGHA1. BISGhi SC (the smallest BC SC) showed the highest expression of ISGs (Fig. 5c, f) and was expanded at time point B in 2/6 infants (Fig. 5d, e and Supplementary Fig. S6b). This evidence concerns the gene IGHG1 and breast cancer.