TUBB2B and congenital fibrosis of the extraocular muscles: No null alleles are published for Tuba1a, Tuba1b, Tuba1c, Tubb2a, or Tubb2b. ENU mutagenesis efforts have identified alleles in Tuba1a [7, 40, 41] and Tubb2b [42], and a mouse model of CFEOM for Tubb3 has been made [31].