TP53 and neoplasm: Additionally, overexpression of the p53β isoform in 786-O and CAKi-1 cells has been shown to lead to a higher level of apoptosis regardless of p53 status [33]; however, Diesing and colleagues have shown no association between p53 isoforms, advanced tumor stages, and clinical features of RCC patients (a 55 patient cohort) [25].