Most recently, Hata et al. reported that a cancer multi-gene panel testing demonstrated mutations of phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) and deletions of cyclin-dependent kinase inhibitor 2A/B (CDKN2A/B), methylthioadenosine phosphorylase (MTAP), and lysine demethylase 6A (KDM6A) in one case of GCTST, with malignant transformation [10]. This evidence concerns the gene PIK3CA and giant cell tumor of soft tissue.