Various BK concentrations (10, 30, 100, 300, and 1,000 nM) were screened for determining the optimal concentration for its priming effect on three neuroblastoma lines (CHP-134, IMR-32, and CHP-100) in response to 1, 3 and 30 ng/mL SDF-1. Here, CXCL12 is linked to neuroblastoma.