PIK3CA and neoplasm: Nonetheless, recent sequencing studies have implicated the PI3K, MAPK, and TP53 pathways as key oncogenic mechanisms driving the development of angiosarcoma.[6–10] In 2019, Cao et al[21] detected somatic alterations in PIK3CA and PIK3R1 (the 85 kDa regulatory subunit of PI3K) in the tumor specimen of a 51-year-old female patient with primary splenic angiosarcoma.