NPAS2 and neuroblastoma: Interestingly, addition of lactate to neuroblastoma cells stimulates NPAS2/BMAL1 activity (Rutter et al., 2001) but its release only showed a rhythmicity in response to BMAL1 knockdown in human bone osteosarcoma epithelial cells (U2OS) cells (Krishnaiah et al., 2017).