Interestingly, a missense mutation in IQGAP1, S459L, was identified in a family predisposed to oral squamous cell carcinoma (OSCC) and this variant was found to be more active than wild-type IQGAP1 in tissue cultures, based upon monitoring levels of MAPK and PI3K signaling [61]. Here, IQGAP1 is linked to oral cavity squamous cell carcinoma.