PIK3IP1 and cancer: Moreover, PIK3IP1 mRNA levels were not only considerably lower in Ras-mutant and Raf-mutant cancer cells compared with normal cells (Supplementary Fig. 8a), but a131-mediated and a166-mediated induction of PIK3IP1 was also significantly attenuated in these cancer cells, unlike normal cells (Fig. 5c; Supplementary Fig. 8b).