Trying to understand the mechanisms of chemotaxis,during which biological cells move in the presence of chemical gradients, is a challenging and fascinating problem. Chemotaxis and cell migration are key components in a multitude of biological processes, including neuronal patterning, wound healing, embryogenesis, and cancer metastasis. Even though many of the key components, cell migration remains a poorly understood process. In this talk, I will present our modeling and experimental efforts aimed towards a better quantitative and mechanistic understanding of chemotaxis and cell motility.