CTTNBP2 and TNF receptor 1-associated periodic fever syndrome: However, loss of the ubiquitination site within a predicted intrinsically disordered region of the ORF4 protein (alteration of 50th leucine to proline) (Figure 1B) observed in seven sequences isolated from fulminant hepatic failure (FHF) and acute hepatitis patients suggests that viruses producing proteasome-resistant ORF4 may be a contributing factor to negative patient outcomes [19].