The plasma PK of dasatinib (a Cyp3a metabolized drug given throughout therapy to treat BCR-ABL+ acute lymphoblastic leukemias) was evaluated after two separate single oral gavage doses of 10 mg/kg to determine the effects of VD3 status, sex and age (8 wk vs. 10 wk) on plasma PK using a nonlinear mixed effects PK modeling approach. The gene discussed is ABL1; the disease is acute lymphoblastic leukemia.