Variants of AXIN1 and AXIN2 genes, or of the other components of the signaling pathway, may influence the gene activity and also β-catenin mRNA levels [7], therefore, being involved in the development and/or progression of diseases such as cryptorchidism [8], congenital septal heart defects [9], hepatocellular carcinoma [10], colorectal carcinoma [11], and lung and other types of cancers [12]. The gene discussed is AXIN2; the disease is heart septal defect.