The signaling axis orchestrated by OX40L-OX40 is a T-cell costimulatory pathway implicated in multiple autoimmune diseases, such as atopic dermatitis (AD). Antibodies targeting this pathway have proven useful at treating AD in the clinical setting. Earendil Labs recently presented data regarding HXN-1021, an anti-OX40L antibody with potent activity and extended half-life, in vivo.