CYP2D6 and breast cancer: However, this finding was not in accordance with other recent studies reported that CYP2D6*10 genotype is more common in the intermediate and poor metabolizer BC patients from south Indian (Kiyotani et al., 2010), and china (Xu et al., 2008; Zeng et al., 2017; Wei et al., 2020), with increased recurrence and reduced survival rates.