The general treatment plan will consist of chemotherapy for standard-risk participants and chemotherapy followed by HSCT for high risk participants in first relapse of B-precursor ALL or lymphoblastic lymphoma. Remission induction for all participants consists of three blocks of therapy, wherein the first block is a novel immunotherapy regimen that includes cytotoxic chemotherapy, rituximab and infusion of haploidentical natural killer (NK) cells. Standard-risk patients will continue to receive chemotherapy for a total duration of approximately 2 years. High-risk patients will be candidates for HSCT and will proceed to transplant once a suitable donor is found and the patient achieves negative MRD.