PML and acute promyelocytic leukemia: There also have been reports of t-APL occurring following treatment with other topoII poisons (e.g., etoposide) used for lymphomas and various solid tumors, as well as Langerhans cell histiocytosis.12,25,43 To determine whether topoII–mediated cleavage is relevant to other drugs associated with t-APL, we also have studied a patient in whom APL developed after treatment for laryngeal carcinoma that included etoposide and doxorubicin.33 Etoposide and its metabolites and doxorubicin induced topoII to cleave DNA at the PML and RARA translocation breakpoints.