However, in the presence of estradiol, PI3K/AKT/mTOR signaling pathway activation levels were higher in ERβ1/5-expressing lung cancer cells than those in ERβ1-expressing cells, suggesting that the interaction between ERβ1 and ERβ5 potentiated the effects of ERβ1 in non-genomic signaling. The gene discussed is PIK3CA; the disease is lung carcinoma.