Dependence on maintained expression of LRP5Δ666–809 was also observed for expression of the endogenous β-catenin target gene MYC [22], which is commonly overexpressed in parathyroid tumors [5], as the MYC mRNA level was significantly reduced in sHPT-1 parathyroid cells transfected with siLRP5Δ666–809 and siLRP5tot, but not with siLRP5wt, control siRNA, and control siLRP5tot (Figure 4A). Here, MYC is linked to tumor of parathyroid gland.