ERBB2 and ovarian carcinoma: Furthermore, as demonstrated in HER2-overexpressing ovarian cancer models, accelerated internalization leads to faster lysosomal trafficking where proteolytic enzymes more efficiently cleave the linker, resulting in significantly higher intra-tumoral MMAE concentrations compared to serum levels (Zhu et al., 2021).Since overexpression of HER2 is connected to more aggressive disease, a higher risk of metastasis, and lower overall survival rates, it is strongly associated with a bad prognosis in urothelial cancer (Jimenez et al., 2001; Gan et al., 2021).