AQP1 and neoplasm: The analysis between blood group gene expression and tumor grade showed that the expression of these antigen genes had significant associations with grades in 10 tumor types, which are LGG, HNSC, STAD, CESC, PAAD, LUAD, OV, UCEC, KIRC and LIHC, and that the high expression of five genes (SLC14A1, P1, ERMAP, AQP1, FUT6) was associated with lower grades in UCEC and KIRC.