Eight other rare gene rearrangements have been described in APL fusing RARA to promyelocytic leukemia zinc finger (PLZF also known as ZBTB16),[6] nucleophosmin(NPM1), nuclear matrix associated (NUMA1), signal transducer and activator of transcription 5b (STAT5B), protein kinase A regulatory subunit 1α (PRKAR1A), factor interacting with PAPOLA and CPSF1 (FIP1L1), BCL6 corepressor (BCOR) or oligonucleotide/oligosaccharide-binding fold containing 2A (OBFC2A also known as NABP1) genes. Some of these rearrangements are ATRA-sensitive or have unknown sensitivity to ATRA because they are so rare; STAT5B/RARA and PLZF/RARA are known to be resistant to ATRA.[1]