  We present a new global QCD analysis of nuclear parton distribution functions
and their uncertainties. In addition to the most commonly analyzed data sets
for the deep-inelastic scattering of charged leptons off nuclei and Drell-Yan
di-lepton production, we include also measurements for neutrino-nucleus
scattering and inclusive pion production in deuteron-gold collisions. The
analysis is performed at next-to-leading order accuracy in perturbative QCD in
a general mass variable flavor number scheme, adopting a current set of free
nucleon parton distribution functions, defined accordingly, as reference. The
emerging picture is one of consistency, where universal nuclear modification
factors for each parton flavor reproduce the main features of all data without
any significant tension among the different sets. We use the Hessian method to
estimate the uncertainties of the obtained nuclear modification factors and
examine critically their range of validity in view of the sparse kinematic
coverage of the present data. We briefly present several applications of our
nuclear parton densities in hard nuclear reactions at BNL-RHIC, CERN-LHC, and a
future electron-ion collider.
