Cover Feature: Identification of Novel Oxazolo[5,4‐ d ]pyrimidines as IL‐33 Inhibitors for Immuno‐Oncology Therapy (ChemBioChem 6/2026)

A rationally designed KYH1942 disrupts the IL-33/ST2 signaling axis by binding to IL-33. IL-33 (pink) engages the ST2 receptor on Treg cells (green), leading to activation of Treg cells characterized by elevated expression of FOXP3. The cover illustration depicts suppression of this pathway by an IL-33–ST2 PPI inhibitor (KYH1942, blue sticks), resulting in reduced FOXP3 expression and diminished Treg cell activation (dark brown). A magnified view highlights KYH1942 occupying a hydrophobic pocket of IL-33, illustrating molecular basis for blockade of the IL-33/ST2 interaction. More details can be found in the Research Article by Sang-Jun Ha, Taebo Sim, and co-workers (DOI: 10.1002/cbic.202500417).