Cell and gene-modified cell therapies hold immense potential for transforming healthcare, but they come with unique complexities in chemistry, manufacturing, and controls (CMC) that can result in setbacks, such as manufacturing comparability failure, clinical holds, product approval delay, and even manufacturing issues during post-market surveillance. As more therapies are being developed, it is crucial to explore and overcome the CMC challenges that can impede program and market progress. This article will focus on addressing CMC issues for cell and gene therapy (CGT) products through a robust process and an analytical development program.