Figure 2.

(A) Development potential of iPSCs and ESCs into ectoderm, mesoderm, and endoderm multipotent cells, highlighting the formation of MSCs. (B) Osteosarcoma development may result from an abnormal differentiation of MSCs. Mutations occurring in osteoblastic, chondrogenic, or fibroblastic ancestor cells may originate genetically altered cells that contribute to bone sarcoma formation. (C) In a clonal-hierarchical model, new mutations occurring in CSCs may lead to clonal evolution, and multiple CSC clones may co-exist within the tumor, which altogether constitutes a complex tumor heterogeneity. iPSCs—induced pluripotent stem cells, ESCs—embryonic stem cells, HPSCs—hematopoietic progenitor and stem cells, and MSCs—mesenchymal stem cells. Created with BioRender.com (figure created on 28 March 2023).