There are also many factors that complicate both the design and delivery of tumor-suppressing chemotherapy, such as the presence of efflux pumps, multi-drug resistance, p53 mutations, off-target interactions, angiogenic vasculature, mitotic slippage, heterogeneity of the tumor cells, their higher mutability, alterations in tubulin isotype expression over time and the potential to develop drug resistance [36,37]. This evidence concerns the gene TP53 and neoplasm.