KLF4 and osteosarcoma: Interestingly, KLF4 has also been shown to play a role in maintaining the stemness of CSCs; for instance, KLF4-overexpressing osteosarcoma cells displayed characteristics of osteosarcoma CSCs: increased tumour sphere-forming potential, enhanced levels of stemness-associated genes, and great chemoresistance to adriamycin and CDDP [22].