Response to: Determining Allele-Specific Protein Expression (ASPE) Using a Novel Quantitative Concatamer Based Proteomics Method.

A recent publication in this journal reported the application of a targeted proteomic strategy using a quantitative concatemer (QconCAT) standard to the assessment of allele-specific expression of UGT2B15 claiming this methodology to be a "novel" approach (J. Proteome Res. 2018, Doi: acs.jproteome.8b00620). While the application is not common, the method has previously been described and reported by our group, in relation to the quantification of CYP2B6 alleles, (J. Proteome Res. 2013, 12, 5934-42) to assess the expression of a prevalent polymorphism in a Caucasian population.