Nguyen Huu et al. classified the samples into 4 categories based on the distribution and intensity of IHC staining of WWP1 in BC tissues: Category 1 exhibited no or low staining; Category 2 displayed heterogeneous staining resembling the staining pattern of normal breast tissue, characterized by moderate or strong nuclear staining and minimal cytoplasmic staining in approximately 50% of tumor cells; Category 3 showed homogeneous, moderate to intense nuclear staining; and Category 4 presented homogeneous, moderate to intense nuclear staining along with cytoplasmic staining. This evidence concerns the gene WWP1 and breast cancer.