Soy diet in combination with 1,25(OH)2D treatment was able to achieve a further reduction of tumor growth, associated with upregulated messenger expression levels of antiproliferative (p21, IGFBP-3) and pro-apoptotic (Bcl-2 associated X; Bax) genes and downregulation of antiapoptotic (B-cell lymphoma 2; Bcl-2) and cell cycle promoting gene cyclin D1. This evidence concerns the gene CDKN1A and neoplasm.