In this study we investigated the presence of endogenous T-cells recognizing private tumor-associated antigens and predicted neoantigens. To this end, HLA-I and HLA-II restricted tumor associated antigens (TAAs) and neoantigens were respectively identified and predicted. Of interest, circulating T-cells targeting both Mass spectrometry (MS)-identified TAAs and predicted neoantigens were identified in virtually all pediatric BCP-ALL patients, extending up to two years on remission.