Overexpression or knockdown of DDA1 in lung cancer cells induced increase or decrease, respectively, in the expression of cyclin D1, cyclin D3, cyclin E1 and cyclin B1; increased expression of these cyclins is indicative of proliferation, G1 to S‐phase transition and subsequently M‐phase progression (Fig. 5A). This evidence concerns the gene CCNE1 and lung carcinoma.