Generally, two modes of action of the Tid proteins can be discerned to date: i) interaction with cytosolic molecules, such as the APC tumor suppressor [7,13], a central component of the Wingless/Wnt pathway and the E-Cadherin mediated signalling or the Inhibitor of IKB in the NFκB signalling [11], crucial for driving the expression of regulators of cell cycle control, or ii) binding to receptors mediating the activation of signalling pathways, e.g. Ptc [6,7] and ErbB-2 [15]. The gene discussed is ERBB2; the disease is neoplasm.