NFATc1-IN-1 (also known as compound A04) is a highly effective inhibitor of osteoclast formation induced by RANKL, with an IC50 of 1.57 μM. It exerts its anti-osteoclastogenic effects by attenuating the RANKL-induced nuclear translocation of NFATc1. Due to its remarkable properties, NFATc1-IN-1 holds significant potential for advancing research related to osteoclastic diseases [1].