Secreted effector that interacts with and inhibits host apoplastic pathogenesis-related papain-like cysteine proteases (Probable). Inhibition of host proteases by a pathogen extracellular protease inhibitor forms a specific type of defense-counterdefense mechanism between plants and microbial pathogens (Probable). Localizes to host apoplast where it targets defense proteases for inhibition. Expressed during infection of host plant and in germinating cysts. Belongs to the cystatin family.