Relationships between KRT14, KRT15, and KRT10 in human trunk skin. (A) UMAP of human trunk epidermis highlighting KRT15 levels (green) and KRT14 or KRT10 levels (red) across Seurat clusters. (B) sc expression of KRT15 mapped against KRT14 levels in 26,063 keratinocytes in the human trunk epidermis dataset. (C) Distribution of KRT14 and KRT15 expression across all keratinocytes in the dataset. (D) Distribution of KRT15, KRT14, and KRT10 expression in cells exhibiting increasing levels of basal score signature genes (see Materials and methods for definition of composite scores). (E) Expression of G2/M composite score relative to KRT14 and KRT15 levels across keratinocytes in human trunk epidermis. (F) Analysis of average keratin expression level across 17 Seurat clusters matching keratinocyte signatures in the human trunk epidermis dataset. KRT14 (red, circle), KRT15 (green, square), and KRT10 (blue, triangle) assessed per cluster. Clusters are sorted on the x-axis according to the highest basal score-to-differentiation score ratio. The Seurat cluster showing the highest G2/M composite score, on average, is highlighted. (G) Indirect immunofluorescence with magnified insets of Ki67 and K15 in formalin-fixed, paraffin-embedded human buttock skin. K15 channel has been false-colored with the “Fire” lookup table to show signal intensity. Strongly, Ki67-staining nuclei are frequently K15-low basal keratinocytes. Calibration bar displays the color coding for their corresponding K15 MGV intensities. Scale bar, 50 µm. (H) Comparison of linear pairwise expression of type I and type II keratins KRT15/KRT5 (green, R² = 0.31), KRT14/KRT5 (red, R² = 0.79), and KRT10/KRT1 (blue, R² = 0.84) across all keratinocytes in the human trunk epidermis dataset. (H′) Heatmap summarizing Pearson’s (r) correlations between type I and type II keratins across the dataset.