B.A.BA is a project that aims to make the Paris metro system accessible to all through a combination of technological and human assistance. The technological component is a mobile app that uses beacon technology to locate and guide users through the metro. It is complemented by a "Helping Hand" service of personnel who can provide physical assistance. B.A.BA was inspired by signaling molecules in the endocrine system that aid the transport of proteins, and seeks to have a universal, inclusive impact on disadvantaged groups as well as tourists and residents.