Fluorescence in situ hybridization (FISH) analysis using the PML-RARA DNA probe showed a positive signal pattern (fusion) in 100% of 200 total interphase and metaphase cells examined, confirming the presence of the PML-RARA rearrangement.     ///    "These studies showed that the PML-RARA fusion was present, but the complementary fusion RARA-PML, which is usually detectable, was absent. "