GRK2 and chronic pancreatitis: Immunohistochemical staining of tissue microarrays (TMAs) comprising 33 normal pancreas samples, 28 samples of chronic pancreatitis tissues and 65 PDAC samples (grades 1–3) cornfirmed that ADRBK1 protein was undetectable in all non-neoplastic tissues (chronic pancreatitis and normal pancreas), whereas ADRBK1 staining was readily detectable in 33 out of 65 (51%) PDAC samples (Fig 5B).