DROSHA and breast cancer: Interestingly, the increased Drosha was usually related to pathologic features of the tumor, metastasis and prognosis in non-small-cell lung cancer.6 However, the enhanced nuclear Drosha was inversely correlated with tumor grade (breast cancer)15 or tumor invasion (e.g. human cutaneous melanoma),16 suggesting that the different function of Drosha may be based on different tumor types.