  The first two claims concern the concept of a stem cell; the latter two claims concern carcinogenesis itself: how cancer arises. It’s the latter two theses that Laplane takes to be in tension with the “classical” theory. Laplane argues that CSC theory is more “parsimonious”, because it “explains cancer development, propagation and relapse” from a “limited number of hypotheses” (Laplane 2016, 28). In contrast, the classical view neither predicts nor explains cancer heterogeneity, or relapse, but must invoke special (“additional” or “ad hoc” theories) to explain them, in particular, evolutionary processes.  Moreover, the CSC theory has the advantage that it “connects basic research and intervention by suggesting new therapeutic strategy” (Laplane 2016, 28)