CLDN4 and prostate carcinoma: Previously, we showed, using human prostate cancer biopsy specimens, that higher levels of CLDN3 and CLDN4 expression are found in intermediate and high-risk prostate cancers compared to low and very low risk prostate 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].