Identification of Necessary Information for Treatment Induction in Newly Diagnosed Acute Lymphoblastic Leukemia/Lymphoma

Inclusion Criteria:

* Age 1-18.99 years
* Diagnosis of acute leukemia / lymphoma as below:

  * Acute lymphoblastic leukemia (ALL) with at least 25% bone marrow blasts or definitive evidence of ALL in peripheral blood (in those without an available bone marrow sample).
  * Lymphoblastic lymphoma (LLy) with immunophenotypic evidence of a lymphoblastic population and \<25% bone marrow blasts and less than 1,000 circulating blasts/ microL.
  * Mixed phenotype acute leukemia (MPAL) with or without 25% bone marrow involvement (i.e. patients with either leukemia or lymphoma are eligible).

Exclusion Criteria:

* Pregnant or breastfeeding
* Receipt of prior cancer directed therapy with the exclusion of up to 1 dose of intrathecal chemotherapy, 1 dose of vincristine, or emergency radiotherapy due to organ compromising malignant mass. There is no exclusion for prior steroid therapy.
* Known to be currently ineligible for available SJALL therapeutic studies (e.g. receipt of prohibited therapy, no appropriate SJALL therapeutic study available, enrolled on competing trial, etc.).

Note: The intention of this exclusion criterion is to enroll all newly diagnosed ALL/ LLy/ MPAL patients. If participant is screened as a potential participant for subsequent SJALL and later found to be ineligible due to information obtained during INITIALL, this will not make the participant ineligible for INITIALL.

* Inability or unwillingness of research participant or legal guardian/representative to give written informed consent.
* Major pre-existing abnormalities such as ataxia telangiectasia, Fanconi anemia, Charcot Marie Tooth, etc.