Heme,the precursor of hemoglobin,is a kind of porphyrin compound containing iron ion,which plays an important role in various biological processes(such as oxygen transport,electron transport,gene expression regulation,circadian rhythm and signal transduction).It is known that heme is produced in the mitochondrial matrix,and heme proteins and heme regulatory proteins are widely distributed in various subcellular sites.Given the hydrophobicity and prooxidant properties of free heme,cells must have specific pathways to safely transport heme from within mitochondria to outside mitochondria.

　　On October 19,2022,the team led by Chen Caiyong from Zhejiang University published a research paper titled HRG-9 homologues regulate haem trafficking from haem enriched departments online in Nature magazine,revealing important mechanisms of intracellular heme transport.This study found that HRG-9 and its homologous proteins play a crucial role in heme transport.