We analyzed the expression characteristics for a set of featured genes in each MSC subcluster (Fig. 5c, Supplementary Fig. 14c; Supplementary Data 4) including: (1) the subcluster 1, predominantly observed in the chondroblastic OS lesions BC 20 and BC22 (Supplementary Fig. 14a, b), exhibited relatively high expression of MSC marker NT5E (CD73) with genes VEGFA and TGFBI (Fig. 5c, Supplementary Fig. 14c). Here, VEGFA is linked to breast cancer.