TUBB2B and congenital fibrosis of the extraocular muscles: Based on this evidence, the TUBB2B amino acid substitutions causative of syndromic CFEOM (i.e., p.Ile202Thr, p.Glu421Lys, and likely p.Gly140Ala) hit different domains of the protein and are predicted to have distinct structural/functional impact, though possible functional convergence cannot be ruled out and requires experimental in vitro and/or in vivo analyses.