Clustered monoallelic mosaicism in twins suggests previously unrecognized path of mutagenesis. - Böhnlein J; Maass JG; Dennig J; Burkart S; Kaufmann LT; Brehm M; Göbel K; Kopp-Schneider A; Holland-Letz T; Sprehe LK; Hinderhofer K; Hempel M; et al. (HGG advances, 2026)