– AAK1-IN-4 is a potent and specific inhibitor of adaptor protein-2-associated kinase 1 (AAK1), capable of efficiently penetrating the central nervous system and exhibiting oral bioactivity. It has demonstrated a high degree of selectivity with an AAK1 inhibitory concentration (IC50) of 4.6 nM, a Filt dissociation constant (Ki) of 0.9 nM, and a cellular IC50 of 8.6 nM. AAK1-IN-4 holds promise as a valuable tool in the investigation of neuropathic pain [1].