GRB2 and prostate carcinoma: Another phenolic acid, GA (>50 μM), was reported to have dose-dependent effects in the regulation of intracellular proteins in prostate cancer: these included the inhibition of growth factor receptor-bound protein 2 (GRB2), PKC, NF-κB p65, JNK, ERK1/2, p38 and phospho-Akt.