Classic known cell-specific genes described in previous studies were used to annotate cell clusters: intermediate cells (IC, Kcnj10+, Kcnj13+, Met+, Nrp2+, Cd44+); basal cells (BC, Tjp1high, Cldn11+); and MC(Kcnq1+, Kcne1+) [22–24]. Here, CD44 is linked to breast cancer.