We used confocal imaging to identify ANKH mutant cell localisation dynamics, measured ePPi concentrations and altered mineralization level, evaluated ANKH mutant effect on the function of ENPP1 and gene expression of ENPP1, TNAP and PIT-1. We also investigated the involvement of autophagy for potential mutated ANKH protein recycling in the pathogenesis of CPPDD and CMD. The gene discussed is ENPP1; the disease is chondrocalcinosis 2.