Inclusion Criteria:

          -  Patient must have been diagnosed with CML-CP at < 18 years of age.

          -  Patient must have histologic verification of CML-CP at original diagnosis

          -  Patient must be in molecular remission (MR) with a BCR-ABL1 level of =< 0.01% BCR-ABL1
             as measured using the International Scale (IS) by RQ-PCR for >= 2 consecutive years at
             the time of enrollment

               -  Please note: The lab evaluating disease status and molecular response for this
                  study must be College of American Pathology (CAP) and/or Clinical Laboratory
                  Improvement Amendments (CLIA) certified (United States [US] only), sites in other
                  countries must be certified by their accredited authorities. All labs must use
                  the International Scale guidelines with a sensitivity of detection assay =< 0.01%
                  BCR-ABL1 and be able to report results in =< 2 weeks

          -  Patient must have received any TKI for a minimum of 3 consecutive years at time of
             enrollment

          -  Patient agrees to discontinue TKI therapy

          -  REGULATORY REQUIREMENTS

          -  All patients and/or their parents or legal guardians must sign a written informed
             consent

          -  All institutional, Food and Drug Administration (FDA), and National Cancer Institute
             (NCI) requirements for human studies must be met

          -  ELIGIBILITY FOR PATIENT-REPORTED OUTCOMES (PROs):

          -  Age >= 8 years at the time of enrollment

          -  Ability to understand English or Spanish

          -  Cognitive ability to complete instruments according to the primary team

          -  ELIGIBILITY FOR AAML18P1 NEUROCOGNITIVE STUDY:

          -  Patient must be 5 years or older at the time of enrollment

          -  English-, French- or Spanish-speaking

          -  No known history of neurodevelopmental disorder prior to diagnosis of CML (e.g., Down
             syndrome, Fragile X, William syndrome, mental retardation)

          -  No significant visual or motor impairment that would prevent computer use or
             recognition of visual test stimuli

        Exclusion Criteria:

          -  Known T3151 mutation

          -  Additional clonal chromosomal abnormalities in Philadelphia chromosome (Ph) positive
             (+) cells at any time prior to enrollment that include "major route" abnormalities
             (second Ph, trisomy 8, isochromosome 17q, trisomy 19), complex karyotype or
             abnormalities of 3q26.2

          -  History of accelerated phase or blast crisis CML

          -  Female patients who are pregnant

          -  Lactating females are not eligible unless they have agreed not to breastfeed their
             infants

          -  Female patients of childbearing potential are not eligible unless a negative pregnancy
             test result has been obtained