The critical roles of PRMTs in cancers have made them as attractive therapeutic targets. Recent efforts have led to developing numerous inhibitors of PRMTs with potent and selective activity. The significant anti-tumor effect in preclinical studies has provided a strong rationale for clinically evaluating the inhibitors of PRMT5 and type I PRMTs in cancer patients. Despite these promising progresses have been made, targeting PRMTs is still in its infancy. Key future directions include identifying biomarkers for prediction of the responsiveness, improving the selectivity of PRMT inhibitors, and exploring combination therapies. For example, our study demonstrated that combinational treatment of PRMT5 plus autophagy inhibitors has a synergistic effect in triple negative breast cancer (Brobbey et al. Scientific Reports, 2023).