We also attempted to confirm whether knockdown or overexpression of THBS1 would affect osteosarcoma cell dedifferentiation, and a sphere formation assay showed that knocking down THBS1 significantly reduced the number and diameter of sarcospheres, while overexpression of THBS1 increased the diameter of sarcospheres, indicating that THBS1 affects the dedifferentiation of osteosarcoma cells (Figure 2D). This evidence concerns the gene THBS1 and osteosarcoma.