CD44 and cancer: Particularly, two studies provided evidence that the FOXO3 transcription factor is essential for CD44 expression in pancreatic cancer cells [165,166]; particularly, a complex signaling/metabolic pathway involving FOXO3/c-AMP/peroxisome proliferator-activated receptor-γ co-activator-1β (PCG-1β)/pyruvate dehydrogenase-A1 is essential for CD44 expression and cancer stem cell properties in pancreatic cancer cells [166].