CLDN4 and cancer: Martin et al. found higher levels of CLDN3 and CLDN4 expression in higher-risk human prostate cancer specimens compared to lower risk cancer specimens [Martin DT, Lee JS, Liu Q, Galiana G, Sprenkle PC, Humphrey PA et al.: Targeting prostate cancer with clostridium perfringens enterotoxin functionalized nanoparticles co-encapsulating imaging cargo enhances magnetic resonance imaging specificity, Submitted].