CPZ and neuroblastoma: However, in a concentration-dependent fashion (the 0–100 μM range has been tested), CPZ strongly decreased ATP (Figure 3A) and total protein (Figure 3B) levels/well in neuroblastoma cells, causing statistically significant (p < 0.01) impacts even at 5 μM concentration and showing close the maximal toxicity at 50 μM (Figure 3).