TRPA1 and neoplasm: The results were also confirmed in a more complex cell culture system, such as tumor spheroids, in which there was an accumulation of ROS, especially in the inner part, which determined an increase in intracellular Ca2+ concentration that was suppressed by TRPA1 inhibitor (AP-18) or by N-acetyl-l-cysteine (NAC) treatment (Fig. 5b-c).