CCND1 and Nijmegen breakage syndrome: Thus, it is tempting to speculate that the observed shift of the p-AKT/p-ERK ratio to high p-AKT/high p-ERK in FZD2 siRNA treated NBs, which was associated with reduced cyclin D1 expression levels, translates the p-ERK/p-AKT decision towards decreased proliferation of NB cells.