In malignancies, a decrease in the tissue PACAP level was described in colon carcinoma [45], non-small cell lung cancer [45], renal tumors [46], papillary thyroid carcinoma [47], pituitary adenoma [48], pancreatic ductal adenocarcinoma [49], and insulinoma [50], while an increase was observed in neuroblastoma [51,52], ductal and lobular breast carcinoma [53], cervical cancer [54], and prostate tumor [46]. This evidence concerns the gene ADCYAP1 and thyroid gland papillary carcinoma.