Cell calcification suppressing proteins, and genes of the proteins

This invention provides cell-calcification inhibitory proteins as well as genes encoding the proteins. Based on the discovery of a novel isoform gene of the c-erg gene (herein referred to as “C-11 gene”) which is an erg gene derived from chickens, the nucleotide sequence of the gene has been determined, and then the expression of a protein encoded by such gene (herein referred to as “C-11 protein”) has been confirmed. Further, it has been discovered that when the c-erg or C-11 gene is introduced into osteoblasts, the calcification of the cells is inhibited.