MAD2L1 and breast carcinoma: In addition, downregulation of MAD2 in MKN45 cells significantly reduces the growth of xenografts in immunocompromised mice, concomitant with a decrease in MMP1 and SNAI2. Based on this, we hypothesize, what is known in breast cancer 33, that SNAI2 controls MMP1 expression in GCSCs.