In different tumor subtypes, cells within the tumor population exhibit functional heterogeneity and tumors are formed from cells with various proliferative and differentiation capacities.[4] This functional heterogeneity among cancer cells has led to the creation of multiple propagation models to account for heterogeneity and differences in tumor-regenerative capacity: the cancer stem cell (CSC) and stochastic model. However, certain perspectives maintain that this demarcation is artificial, since both processes act in complementary manners as far as actual tumor populations are concerned.[1]