A covalent compound selectively inhibits RNA demethylase ALKBH5 rather than FTO.

-Methyladenosine (mA) is the most prevalent mRNA modification and is required for gene regulation in eukaryotes. ALKBH5, an mA demethylase, is a promising target, particularly for anticancer drug discovery. However, the development of selective and potent inhibitors of ALKBH5 rather than FTO remains challenging.