A decreasing trend is seen in CUL3 protein levels in human lung cancer cell lines A549, H2030, H522 compared to human bronchial epithelial cells. A) Western blot for Cul3 expression in human cell lines. Hela = cervical cancer, 293T = kidney, HBEC = immortalized bronchial epithelial, A549 and H522 = stage 2 lung adenocarcinoma, H2030 = stage 4 lung adenocarcinoma, HCT116 and DLD1 = colorectal cancer. B) Quantification of western blots analyzing Cul3 expression from 3 separate cell lysates. (t-test P-values: HBEC vs. A549 = 0.12, HBEC vs. H2030 = 0.07, HBEC vs. H522 = 0.18)