Functional domains of the PLZF protein and structure of the PLZF-RAR and reciprocal RAR-PLZF proteins generated in t(11;17)(q23;q21) APL. PLZF-RAR always contains the N-terminal POZ/BTB-self-association domain. Heterogeneity in the PLZF gene breakpoint can yield PLZF-RAR fusion proteins, including either the first two or first three zinc fingers of PLZF. The reciprocal RAR-PLZF protein can bind to PLZF binding sites and contains the last six or seven of the nine PLZF zinc fingers linked to the AF1 activation domain of RAR rather than the PLZF repression domains.