Recently, we observed high amounts of ATM kinase activation (which promotes chemotherapy resistance) in patient-derived neuroblastoma cell lines (PDCLs) and patient-derived xenografts (PDXs) (48), and also in PDCLs of other histologies (rhabdomyosarcoma, osteogenic sarcoma, triple negative breast cancer, and colorectal cancer) that have the ALT phenotype (47). This evidence concerns the gene GPT and triple-negative breast carcinoma.