Specifically, an increase in SMOX activity parallels the progression of prostate, liver and gastric carcinoma (Goodwin et al., 2008; Chaturvedi et al., 2015; Murray-Stewart et al., 2016; Hu et al., 2018), while high polyamine catabolic enzyme levels have been positively related to a good prognosis in breast cancer patients (Wallace et al., 2000; Cervelli et al., 2010). This evidence concerns the gene SMOX and breast cancer.