GADD45B and retinoblastoma: Similarly, qRT-PCR results showed that levels of GNB1, growth arrest and DNA damage-inducible beta (GADD45B), dual specificity phosphatase 1 (DUSP1), and angiotensinogen (AGT) were 4.0, 2.5, 2.1, and 1.3 times higher in RB tissues than in normal tissues, respectively.