Cell lines have become an essential research tool in life science studies and are used by researchers in a variety of fields. However, a certain proportion of cell lines are mislabeled or replaced by cells derived from different individuals, tissues, or species. Misidentification of cell lines in the publication of scientific papers has been overlooked for many years. As a result, thousands of misleading and potentially erroneous papers have been published using misidentified cell lines. Today, methods have been established to authenticate cell lines of human origin, and it is possible to determine if a cell is misidentified. However, still about 8% of human-derived cells deposited in cell banks are found to be misidentified. The problem of misidentification of cell lines is deep-rooted and can only be eradicated through the continuous efforts of all scientists with the same awareness. In this chapter, we make recommendations to scientists and the research community to make cell line authentication a standard practice in laboratories.