ARHGDIB and Leigh syndrome: Among the top findings, i.e., multiple probes targeting the same gene, and/or |Δβ|> 0.20, of common DMPs and differentially methylated promoters in all LS tumor groups (Table 4), the same probes (at least two) were altered similarly in FAP normal mucosa: ARHGDIB, CNTN4, DAPP1, RIMS1, TCN1 (hypomethylated), and FBLIM1, HOXA3, HOXA5, OPLAH, NR5A2, SEPT9, THBS1 (hypermethylated) (Additional Table 2, 3).