ERBB2 and breast cancer: While quercetin decreased ErbB2 tyrosine kinase activity and the phosphorylation of PI3K and AKT om SKBR3 breast cancer cells [55,69], it reduced the phosphorylation of ERK1/2 and AKT phosphorylation and inhibited the NF-κB pathway in HepG2 liver cancer cells [55,70].