PIK3R1 and neoplasm: Amongst these, elevated phosphorylation of Pik3r1, Pik3r3, a G protein–coupled receptor (Gprc5c) and an uncharacterised protein (2310030G06Rik) was specific to PyMT tumours, and p53 tumours were characterised by increased phosphorylation of Vim, Ptrf, Vcl, Fgr, Met and a protein related to heat shock protein 70 kDa.