PIK3R1 and neoplasm: The most striking pattern was found in case 756 where four distinct PI3K mutations were detected amongst the five tumor regions, including two SNVs in PIK3CA (H1047R and E545G) and two hotspot in-frame indels (D569ED and N453del) in PIK3R1. Interestingly, convergent evolution was observed only in patients with relatively short treatment duration (< 100 days) although the association was not significant due to small sample size (p value is 0.14 by Fisher’s exact test).