The Mammalian Protein Atlas will be a new open resource on the web, but also partly an extension of the Human Protein Atlas (HPA), focusing on comparing protein expression from other mammalian species (mouse, macaque, pig and dog to start with) with human protein expression. This will mainly be done using transcriptomics. The Human Protein Atlas program has been selected by the organization ELIXIR as a European core resource, due to its fundamental importance for a wider life science community.