TP53 and neoplasm: However, there are still many open questions: in which cancer types/subtypes will the determination of TP53 status be of greatest benefit; what is the contribution of TP53 variant heterogeneity to tumor phenotype; is the contribution of TP53 isoforms to tumor phenotype large; which drugs will be most effective in tumors with functional and non-functional TP53 pathways [10].