Inhibition of PLC with U73122, protein kinase C with GF109203X, or CXCR4 with AMD3100 significantly potentiated dexamethasone (Dex)-induced mitochondrial membrane potential depolarization, reactive oxygen species production, cytochrome c release, caspase-3 activation, and decreased O2 consumption in B-ALL cells. The gene discussed is CASP3; the disease is acute lymphoblastic leukemia.