Ratio to CT14  predictions of the production of muons from \Wminus (top) and \Wplus (bottom) decays measured in \pPb collisions at \eightnn by the ALICE and CMS  Collaborations. The measured ratio is compared to the one obtained from pQCD calculations with CT14+EPPS16 . All the calculations include the isospin effect. The grey band around the line at unity indicates the uncertainty on the calculations with CT14 PDFs.