cancer stem cells (cscs) have been defined as a unique subpopulation in tumors, endowed with the capacity to initiate tumor progression, maintain self-renewal as well as metastatic potential. recently, more evidence strongly indicates the existence of cscs in solid tumors of wide variety of organs such as breast, brain and stomach. recent studies suggest that a special subpopulation of gastric ...

If both waking and dreaming consciousness are functional, their de-differentiation would be doubly detrimental. Differentiation between waking and dreaming is achieved through neuromodulation. During dreaming, without external sensory data and with mesolimbic dopaminergic input, hyper-cholinergic input almost totally suppresses the aminergic system. During waking, with sensory gates open, amine...

Cell differentiation in multicellular organisms has the obvious function during development of creating new cell types. However, in long-lived organisms with extensive cell turnover, cell differentiation often continues after new cell types are no longer needed or produced. Here, we address the question of why this is true. It is believed that multicellular organisms could not have arisen or be...