IQGAP1 and hepatocellular carcinoma: Interestingly, more moderate (∼2.5-fold) increase in cyclin D1 and IQGAP1 expression in the livers of younger Iqgap2 −/− mice without HCC was also evident, establishing that IQGAP1 upregulation and cyclin D1 activation predated histological evidence for HCC development in these mice [27].