Accordingly, we investigated expression profiles of cells within clusters 1 and 2 and found that 275 genes were expressed significantly in these cells compared with cells in other clusters, including SOX9, KRT5, a basal marker [21], and KIT, which is often overexpressed in tuft cell-like cancers [11, 13] (Table S3 and Fig. 6g-i). This evidence concerns the gene SOX9 and cancer.