TP53 and neoplasm: Figure 8A shows that the p53-overexpressing cells formed smaller and fewer number of tumor spheres, while the Cav-1-overexpressing cells exhibited larger and greater number of tumor spheres as compared to vector-transfected BSW control cells, thus validating the inhibitory role of p53 and the promoting role of Cav-1 in the CSC induction by SWCNTs.