“…Part of this information has who have a high probability of treatment failure has been previously published [ 1,3 , 91. recently become possible through the definition of certain DEFIN,TION OF STUDY POPULAT,ON presenting prognostic factors. These include such clinical and/or biologic features as the level of the white blood Imunophenotyping studies, including cytoplasmic cell (WBC) count, age, degree of organomegaly, gender, and surface P chain expression to define pre-B or B cells, leukemic cell ploidy and/or karyotype, platelet count, respectively, and expression of E rosette receptors and/ presence of a mediastinal mass, race, cell morphology, or pan-T cell antigens to define T cell leukemia, were immunophenotype, rapidity of achieving remission, the performed on the lymphoblasts of all patients included in presence of initial central nervous system (CNS) leukemia, glucocorticoid receptor levels in blasts, and blast From the St. Jude Children's Research Hospital, Memphis, Tennessee PAS positivity [1][2][3][4][5][6][7][8][9][10][11][12]. Furthermore, the relative impor-(W.C.) Pediatric Oncology Group Statistical Office, Gainesville, tanCe of many Of these prognostic factors has been shown Florida (J.B.), University of Mississippi, Jackson (J.P.), M.D.…”