RB1 and retinoblastoma: Recently, Rushlow et al. [15] showed that a remarkable number of patients with retinoblastoma carry mosaic mutations; the researchers found mutations in 92.6% of cases via a combination of full sequencing and deletions/duplication analysis of RB1. Moreover, they found additional mutations in cases with clearly normal results using PCR-based methods, so the detection rate increased to 94.8% [15].