  In this talk, we present our recent work on next-to-leading order (NLO)
nuclear parton distribution functions (nPDFs), which we call EPS09. As an
extension to earlier NLO analyses, we complement the deep inelastic scattering
and Drell-Yan dilepton data by inclusive midrapidity pion production
measurements from RHIC to reduce the otherwize large freedom of the nuclear
gluon densities. In addition, our Hessian-type error analysis leading to a
collection of nPDF error sets, is the first of its kind among the nPDF
analyses.
