Cancer stem cell hypotheses: impact on modern molecular physiology and pharmacology research.

Although questioned on several occasions, the existence of cancer stem cells (CSCs) has been confirmed by a number of studies on experimental animal models. Nevertheless, it was shown that CSC hypotheses have several limitations and inconsistencies regarding the explanation of CSC origin, CSC identification and isolation, possible heterogeneity within CSC population, as well as methodology issues in some studies that were carried out in order to prove CSC existence. The aim of this article is to give a short and comprehensive review of recent advances concerning CSC hypothesis and to describe its impact on modern molecular physiology and pharmacology research.