PAPPA and nonpapillary renal cell carcinoma: To determine the underlying mechanism of the regulatory effect of PAPP‐A on ccRCC cell proliferation, migration and invasion, we transfected ccRCC cells with PAPP‐A or control plasmid, and the expression levels of phosphorylated (p‐) JNK, JNK, cyclin D1, p‐GSK‐3β Ser9, GSK‐3β and β‐catenin were characterized by western blot.