Figure. CTNNB1 mutation in plexiform-type ameloblastoma. (A) Sequence of exon 3 of CTNNB1 in case 3. Codon 33 was affected in 1 allele. Alteration from TCT to TGT caused an amino acid substitution from serine to cysteine at the glycogen synthase kinase-3ß (GSK3-ß)-phosphorylation site of CTNNB1. (B) Histological features of case 3. This case shows typical plexiform-type ameloblastoma characterized by interdigitating cords of epithelial cells and scant stellate reticulum. Original magnification: x100. Scale bar: 100 µm.