Interestingly, it is becoming apparent that STAT3 is an important molecular player that allows glioma cells to promote the activity of microglia; reciprocally microglia facilitate tumor survival, growth and the spread of glioma cells (Zhang et al., 2009; Wu et al., 2010; Wei et al., 2013; da Fonseca and Badie, 2013). Here, STAT3 is linked to central nervous system cancer.