Figure 1.

Schematic overview regarding parafibromin functions. Parafibromin is a tumour-suppressor protein which regulates apoptosis, cell-cycle transition, growth factor gene expression (such as insulin-like growth factors I and II), the tumour-associated wingless type (Wnt) pathway, as well as the polymerase associated factor 1 (PAF1) complex. Loss of parafibromin expression through mutational inactivation of the HRPT2 gene could in theory affect one or several of these molecular branches, which in turn would propagate parathyroid tumorigenesis.