The goal of this project is to develop methods for improving the safety of human pluripotent stem cell-based therapies. The methods we have developed are based on in-depth molecular analysis of stem cells and their derivatives. We have developed the largest, most comprehensive database of molecular profiles of thousands of stem cell lines as well as adult stem cell lines and primary human tissues. This has allowed us to benchmark our progress toward producing quality-controlled cells for clinical use. Among our accomplishments beyond the database are new methods for purging cultures of potentially dangerous undifferentiated cells, capturing single circulating tumor cells from the bloodstreams of melanoma patients, and the first successful full RNA sequencing of single cells. These new tools will improve the quality of research and clinical development throughout the stem cell community. We have accomplished all of our original milestones and are extending the work to include new methods.