More importantly, given that demonstration of protein functionality certifies a protein’s existence [7, 8], the demonstration of DEspR expression in >50 % of CSCs in four different cancer tissue types by FACS analysis and DEspR functionality via blocking antibody inhibition of CSC growth in all four different cancer tissue type CSCs—glioblastoma, triple negative breast cancer, non-small cell lung cancer and pancreatic ductal adenocarcinoma, provide compelling evidence of the existence of DEspR protein based on UNI-PROT criteria and standards in the field [7, 8]. This evidence concerns the gene FBXW7-AS1 and pancreatic ductal adenocarcinoma.