Keap1-Nrf2-IN-13 is a Keap1-Nrf2 protein–protein interaction (PPI) inhibitor with an IC 50 value of 0.15 μM. Keap1-Nrf2-IN-13 has strong binding affinities to the Keap1 protein by forming hydrogen bond with the key polar residues (Asn414, Arg415, Arg483, Gln530). Keap1-Nrf2-IN-13 can be used in the research of oxidative stress-related and inflammatory diseases, including pulmonary fibrosis, chronic obstructive pulmonary disorder (COPD) and cancers.