The systems biology strategy based on the molecular, cellular, and organism levels evaluation in vitro and in vivo has been successfully used in its mechanism study, which demonstrated that Realgar-Indigo naturalis formula intensified degradation of promyelocytic leukemia-retinoic acid receptor alpha oncoprotein, increased reprogramming of myeloid differentiation regulators, and enhanced G0/G1 arrest in acute promyelocytic leukemia cells [72]. This evidence concerns the gene RARA and acute promyelocytic leukemia.