PTK2 and colorectal carcinoma: Boothello et al. (2019) revealed that proteoglycans mediate cancer stem cells induced CRC xenograft’s growth in a dose-dependent fashion. Moreover, syndecan-2, a type of proteoglycan, up-regulates MMP-7 expression in colon cancer cells via PKCγ-mediated activation of FAK/ERK signaling (Jang et al., 2017).