One prominent example from this high \documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{upgreek}\usepackage{mathrsfs}\setlength{\oddsidemargin}{-69pt}\begin{document}$\mathrm{ PLL_{delta}}$\end{document} group is FUT2, a fucosyltransferase whose secretor or non-secretor status, determined by its activity, has been linked to susceptibility to various infections and is increasingly studied in the context of cancer risk [46, 47]. This evidence concerns the gene FUT2 and infection.