RRP1B and colorectal carcinoma: To further test the fitness of the above reference genes for use as normalization values in qPCR based assays, we examined the expression of three ribosome biogenesis related genes (BOP, DKC1, and RRP1B) by a TaqMan qPCR assay using selected reference genes ACTB (CV = 34%), HEBP2 (CV = 21%), RAB7A (CV = 17%), and C1orf43 (CV = 16%) for gene expression normalization in 20 CRC pairs (T16 to T35).