They found that the absence of NOD1 correlates with tumor growth, an increased sensitivity to estrogen-induced cell proliferation, and a failure to undergo NOD1-dependent apoptosis in the MCF-7 cells and conversely, overexpression of NOD1 in MCF-7 cells results in inhibition of estrogen-dependent tumor growth and reduction of estrogen-induced proliferative responses in vitro [11]. Here, NOD1 is linked to neoplasm.