Fig. 6

Reanalysis of single-cell RNA sequencing for normal human breast [19]. Epithelial cells in the non-neoplastic breast were separated into 23 subclusters in our analysis (a). Although the number was small, POU2F3-expressing cells were detected (b; n = 390 out of 11,831 cells [3.3%]). These POU2F3-positive cells were either luminal progenitors (CD49f + /EpCAM +) or mature luminal cells (CD49f − /EpCAM +), but almost no basal/stem cells (CD49f + /EpCAM −) [13] (c, d). Small subsets of POU2F3-expressing cells also co-expressed other tuft cell markers; 65 co-expressed SOX9/AVIL and 2 SOX9/GFI1B (e). POU2F3-expressing cells were enriched in clusters 1 and 2; 48% of all the POU2F3-expressing cells (f). The distribution of SOX9- (g), KRT5- (h), and KIT- (i) expressing cells. The cells in combined clusters 1 and 2 markedly express these three genes (Table S3)