Model for calpain 2 involvement in invadopodia dynamics. Integrin engagement and/or EGF receptor activation enhances calpain activity. Calpain cleaves PTP1B, resulting in enhanced phosphatase activity. PTP1B removes the inhibitory phosphate from Y529 of Src, thereby activating Src kinase activity and initiating invadopodia formation. Calpain 2 also functions downstream of Src kinase activity by regulating the disassembly of cortactin from invadopodia.