ADCYAP1 and prostate cancer: However, several studies found PACAP levels of different tissue samples are altered under pathological conditions, with lower PACAP immunoreactivity in different human samples of primary small cell lung cancer, colon, and kidney cancers as compared to healthy tissues, while higher PACAP27 immunoreactivity was found in prostatic cancers as compared to benign prostatic hyperplasia (32, 33).