Schematic representation of C/EBPα functional domain and mutations resulting in C/EBPα dysregulation. (A) Two transactivation domains (TAD1 and TAD2 [pink]) and the basic region and leucine zipper (bZip [blue]) are indicated. The mRNA translated from the ATG at nt1/aa1 encodes the wild-type 42-kDa C/EBPα, whereas the 30-kDa form is translated from ATG at nt358/aa120. (B) The 247dupC mutation results in a truncated N-terminal product with an altered amino acid sequence (green). The 30-kDa product that is generated from the alternative start codon lacks TAD1. (C) The 584_589dup mutation results in amino acid sequence His195_Pro196dup (orange) in TAD2. (D) The 914_916dup mutation results in amino acid sequence Gln305dup (orange) in bZip.