PIK3R1 and sarcoma: Biomarker-driven approaches, such as ERCC1 expression in metastatic melanoma (101) and an 8-gene signature in sarcomas CDKN2A, PIK3R1, SLFN11, ATM, APEX2, BLM, XRCC2, MAD2L2 that may help predict better outcomes (102, 103), offer potential for tailoring therapies.