ABCC4, also known as multi-drug resistance protein-4 (MRP4), is an ATP-binding cassette (ABC) transporter. It plays a crucial role in regulating the transport of endogenous and exogenous substrates, participating in processes like cyclic-adenosine monophosphate (cAMP) homeostasis [1,3,4]. It is involved in multiple biological pathways and is important for the health and function of various tissues [1-9]. Gene knockout (KO) mouse models are valuable for studying its function.

In KO mouse models, Abcc4 deficiency impairs megakaryopoiesis, as fetal liver-derived megakaryocytes from Abcc4-/-mice show impaired proplatelet formation and polyploidization [2]. In the context of cytarabine treatment for acute myeloid leukemia, Abcc4-null mice exhibit enhanced cytarabine-induced hematological toxicity, indicating that ABCC4 protects leukemic and host myeloid cells from cytarabine-mediated insults [5].

In conclusion, ABCC4 is essential for processes such as megakaryopoiesis and protection against certain drug-induced cytotoxicity. The use of Abcc4 KO mouse models has revealed its role in these biological processes and disease-related conditions, providing insights into potential therapeutic strategies for platelet-related disorders and leukemia treatment.