Lung cancer arises from epithelial cells that line the air passages of the lungs. It is the second most common malignancy in the United States; trends suggest that over 228,000 new patients will be diagnosed with lung cancer in 2013. Due to the fact that lung cancer is highly aggressive, it has proven difficult to control. The 5-year survival rate has been shown to be only 15.9%, despite the advances made in terms of diagnosis and treatment. Therefore, we are faced with the problem of finding more effective methods that allow for an earlier diagnosis and the improved treatment of lung cancer. This study attempts to address these issues by investigating Tarsh, a novel molecule that is involved in the regulation of cellular senescence. Previous studies have shown that Tarsh is expressed in normal lung cells, but is significantly downregulated in lung tumors. These studies also determined that Tarsh is likely dependent upon the expression of p53, a tumor suppressor gene. The current study investigated these results, in addition to the biological effects of ectopically increasing Tarsh and/or knocking down p53 expression in two lung cancer cell lines: A549 and H1299 cell lines. It was determined that increasing the expression of Tarsh decreased the rate of proliferation in both cell lines. Additionally, it was shown that the knockdown of p53 increased proliferation in A549 cells. In regards to the migration rate of these cell lines, the overexpression of Tarsh decreased migration in A549 cells, but had no effect on H1299 cells. However, the role of p53 in migration is still unclear. The results of this study suggest that the knockdown of p53 decreases cell migration in A549 cells. This contradicts the fact that H1299 cells do not express p53, yet was found to have the highest migration rate. It is evident that a further investigation is needed to make more concrete conclusions. Nevertheless, the suppressive features of Tarsh on cell proliferation, and possibly migration, make it a promising target of research for lung cancer therapy.