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. Expression is up-regulated during infection of host tomato. Belongs to the cystatin family.