Moreover, Goh et al. [37]established a mouse model of breast cancer tumor formation and metastasis(MMTV-PyMT), and found that MMTV-PyMT mice exhibited a remarkable decrease in tumorgrade (from high-grade to low-grade), and a significant inhibition in metastasis.Thus, miR-940 and MRVI1 levels correlating with tumor grade might be related totumor metastatic potential. This evidence concerns the gene IRAG1 and breast carcinoma.