In acute lymphoblastic leukemia, an association with hypercalcemia in patientswith t (17;19) has been reported, suggesting the possible induction ofPTHrP.(3,14) In this case, thiscytogenetic abnormality was not observed, and high levels of PTHrP were notdetected, thus excluding this mechanism as the primum movens ofhypercalcemia. This evidence concerns the gene PTHLH and acute lymphoblastic leukemia.