Experimental evidence shows that the presence of a nuclear environment affects the outcome of observed quantities. These differences can be explained by several, sometimes orthogonal, mechanisms. A less involved phenomenological approach is to assume that the partonic behaviour at the fundamental level is changed non-trivially. Said changes are encoded into sets of nuclear densities, similar to the proton collinear ones, that have to be determined through global fits. In this article we summarise the latest results towards the determination of nuclear parton densities.