GAPDH and amyotrophic lateral sclerosis: In the present study we have attempted independent confirmation of elevated HERV-K transcripts in the cortex of ALS patients by using exactly the same GAPDH (Glyceraldehyde 3-phosphate dehydrogenase)-normalised RT-qPCR methods for quantification of HERV-K gag, pol and env transcripts as those described previously [19].