Recipient Inclusion Criteria:

          -  Relapsed AML after HLA-matched related or unrelated allogeneic hematopoietic cell
             transplant (per IWG definition of relapse)

          -  For pilot pediatric/young adult patient cohort ≥1 and <18 years of age

          -  For phase 2 adult patient cohort ≥18 years of age

          -  Available original donor (same donor as used for the initial stem cell transplant)
             that is willing and eligible for non-mobilized collection

          -  Patients with known central nervous system (CNS) involvement with AML are eligible
             provided that they have been treated and cerebrospinal fluid (CSF) is clear for at
             least 2 weeks prior to enrollment into the study. CNS therapy (chemotherapy or
             radiation) should continue as medically indicated during the study treatment.

          -  Karnofsky performance status > 60 %

          -  Adequate organ function as defined below:

               -  Total bilirubin < 2 mg/dL

               -  AST(SGOT)/ALT(SGPT) < 3.0 x IULN

               -  Creatinine within normal institutional limits OR creatinine clearance > 60
                  mL/min/1.73 m2 by Cockcroft-Gault Formula

               -  Oxygen saturation ≥90% on room air

          -  Not currently requiring systemic corticosteroid therapy (10 mg or less of prednisone
             or equivalent doses of other systemic steroids are allowed) or any other immune
             suppressive medications

          -  Women of childbearing potential must have a negative pregnancy test within 28 days
             prior to study registration. Female and male patients (along with their female
             partners) must agree to use two forms of acceptable contraception, including one
             barrier method, during participation in the study including throughout the initial
             evaluation period (100 days after CIML NK cell infusion).

          -  Ability to understand and willingness to sign an IRB approved written informed consent
             document (or that of legally authorized representative, if applicable).

        Recipient Exclusion Criteria:

          -  Acute or chronic GvHD with ongoing active systemic treatment.

          -  Circulating blast count >30,000/uL by morphology or flow cytometry (cyto-reductive
             therapies including leukapheresis or hydroxyurea are allowed).

          -  Uncontrolled bacterial or viral infections, or known HIV, Hepatitis B, or Hepatitis C
             infection.

          -  Uncontrolled angina, severe uncontrolled ventricular arrhythmias, or EKG suggestive of
             acute ischemia or active conduction system abnormalities.

          -  New or progressive pulmonary infiltrates concerning for new or uncontrolled infectious
             process.

          -  Known hypersensitivity to one or more of the study agents

          -  Received any investigational drugs within the 14 days prior to CIML NK cell infusion
             date

          -  Pregnant and/or breastfeeding

        Donor Inclusion Criteria:

          -  At least 18 years of age

          -  Same donor as used for the allo-HCT

          -  In general good health, and medically able to tolerate leukapheresis

          -  Ability to understand and willingness to sign an IRB approved written informed consent
             document

        Donor Exclusion Criteria:

          -  Active hepatitis, positive for HTLV, or HIV on donor viral screen

          -  Pregnant