RSPO1 and colorectal carcinoma: However, another study reported that LGR5, which potentiates Wnt signaling upon R-spondin (RSPO) binding, interacts directly with IQGAP1, reduces IQGAP1 phosphorylation, enhances the IQGAP1-RAC1-actin association, and eventually increases cell–cell adhesion of CRC cell lines [35].