sentence: The expression of RTDR1 , HCRT , APOC4 and KRTAP12-3 could not be determined in all 64 tissue samples , resultantly these candidates were excluded from further analysis.Mean C values for the remaining genes ranged from 19.48 ( ± 0.14 s.e.m ) for B2M to 32.30 ( ± 0.19 s.e.m ) for CHRNB4 .