RNA interference (RNAi) provides an exciting revolutionary tool to identify gene function and opens new possibilities for gene-specific therapy. First discovered in 1998, this technology is now being widely used in biomedical researches. Often in the format of cell-based imaging, it provides an approach for high-throughput & high-content screening. This talk will focus on (1) background introduction on RNAi technology, (2) high content cell-based imaging, (3) application on cell cycle research by Lilly cancer group, (4) data analysis issues and statistical methodologies considered.