Of note, mRNA expression analysis showed that the STAT3-regulated genes Mcl-1, Bcl-XL, c-myc and survivin were significantly down-regulated in CSC-derived spheres treated with GL, supporting the hypothesis that the STAT3 signaling is involved in survival of PCa-CSCs (Fig. 3a). This evidence concerns the gene BCL2L1 and posterior cortical atrophy.