PML and acute promyelocytic leukemia: The recent elucidation of PML, a zinc finger protein, as being the target for As2O3 in relation to its activity against APL and provision of evidence that As2O3 interacts with cysteines located in zinc fingers within the RING domain and B2 motif of PML, may serve as inspiration for those interested in discovering a relevant Bi(III) anti-cancer target [3].