ALKBH5 and pancreatic adenocarcinoma: First, the mRNA expression level of m6A regulatory genes were consistent with their copy number status; those genes that mostly showed copy number loss, like METTL3, ALKBH5 and YTHDF family, all showed a tendency of lower expression compared with normal tissues; On the contrary, IGF2BP family, which mainly suffered copy number gain in PAAD patients, showed a tendency of mRNA over-expression in PAAD compared with normal pancreas.