Can we predict protein from mRNA levels?/Wilhelm et al. reply

Prediction of protein levels from mRNA levels has long been fraught with unreliability and a lack of precision. However, Wilhelm et al.1 claimed that using estimated gene-specific translation rates together with mRNA levels accurately predicts protein levels in any given tissue, reporting correlations of approximately 0.9 between predictions and measurements across genes. Here we show that these correlations greatly overestimate the accuracy of per-gene predictions.