Fig 2: Single-cell RNA-sequencing analysis of human healthy control chondrocyte tissue samples.A Seven healthy human chondrocyte clusters. Visualisation of clustering by t-SNE plot of healthy control samples, identified by cell type. B Monocle pseudotime trajectory showing the progression of seven clusters of healthy chondrocytes. C Heat map of scaled gene expression data for the top 10 differentially expressed genes identifying each cluster, with selected genes listed. D Gene expression plots demonstrating high expression of SH3BGRL3 in SH3BGRL3hi fibrocartilage chondrocytes-1, IGFBP5 in IGFBP5hi fibrocartilage chondrocytes-2, CDC20 in CDC20hi cartilage progenitor cells-1, KIAA0101 in KIAA0101hi cartilage progenitor cells-2, EIF5A in EIF5Ahi regulatory chondrocytes, SOX9 in SOX9hi prehypertrophic chondrocytes and TXNIP in TXNIPhi homeostatic chondrocytes. Dot colour corresponds to the level of gene expression in each cell. t-SNE, t-distributed stochastic neighbour embedding. E Representative immunohistochemistry staining of SH3BGRL3, IGFBP5, BIRC5, SOX9, EIF5A and CDC20 in healthy cartilage tissues. Scale bar, left, 500 μm; right, 50 μm, and quantification of positive cells of different areas (superficial, middle, deep) in cartilage tissues displayed by box plot (n = 5). *p < 0.05.

Fig 3: IHC staining of APOL1, SURVIVIN, EFGR, TP63, and SPNS1 in SKCM and normal skin tissue (400×). Expression of APOL1 (A), BIRC5 (C), EFGR (E), TP63 (G), and SPNS1 (I) in normal skin tissues. Expression of APOL1 (B), BIRC5 (D), EFGR (F), TP63 (H), and SPNS1 (J) in SKCM tissues. IHC = immunohistochemical. Images are at 40 × 10 magnification.