PTK2 and colorectal cancer: In metastatic colorectal cancer cells, IL13Rα2 signalling is mediated through a scaffold protein, FAM120A, which activates FAK and PI3K pathways and, indirectly, Src.15 In addition, IL13Rα2 associates with multiple intracellular traffic proteins and its recycling is tightly controlled to regulate the surface membrane expression levels and the amount of free receptor.