Mass Spectrometry Letters (MSL) was first published in December 2010 as a journal representing the Korean Society for Mass Spectrometry (KSMS). MSL is currently the official journal of KSMS. MSL publishes diverse aspects of mass spectrometry, including ever-expanding areas related directly or indirectly to mass spectrometry. MSL publishes brief letters, technical notes, articles, reviews, and tutorials on fundamental research and applications. MSL is now indexed in Scopus and Emerging Sources Citation Index (ESCI).