To investigate the potential role of orphan cyclins in lung cancer, the expression of CCNG1, CCNG2, CCNI, CCNO, CCNY, CNTD1, CNTD2 and SPY1 was investigated in two lung adenocarcinoma cell lines, A549 and NCI-H1395, relative to a primary culture of human fibroblasts by Western blot (Fig. 1a) using antibodies validated against recombinant proteins (Supplementary Fig. S1). Here, CCNG2 is linked to lung cancer.