SLC39A4 and plasma cell myeloma: Besides, ZEB1 has also been proven to confer PC drug resistance by suppressing miR-20331.401 Nabhan et al. found that gemcitabine activity requires caspase activation in multiple myeloma.580 Interestingly, ZIP4 regulates PC cell apoptosis through the cleavage of caspase.581 So far, gemcitabine-based therapies have remained the standard of practice for treating advanced PC.582 Obviously, ZIP4 knockdown combined with gemcitabine may be another promising novel approach for the treatment of PC metastasis and drug resistance.