GRB2 and posterior cortical atrophy: In addition, compared with low-grade PCa, high-grade PCa tissue samples have (1) one more abundant protein complex, (2) increased assembly of 10 protein complexes including the GRB2-SOS1 complex, (3) five less abundant protein complexes, and (4) decreased assembly of 12 complexes including the PPP2CA-PPP2R1A complex.