Localised disruption of E-cadherin-mediated cell–cell adhesion sites was recently observed in invasive human colon carcinoma cells (Shimao et al, 2002) and this disruption was associated with relocalisation of IQGAP1, a Rac1/Cdc42 effector molecule (Kuroda et al, 1998). Here, CDC42 is linked to colon carcinoma.