In the context of advanced high-strength steels, addition of Ni to Fe-Mn-Al-C TRIPLEX steels has provided a pathway towards the development of B2s Fe-Mn-Al-Ni-C steels. Recent investigations on the evolution of B2 precipitates in FCC matrix and its associated influence on the mechanical properties (both micro and nanoscales) of B2s Fe-Mn-Al-Ni-C lightweight steels have highlighted that precipitation of Fe, Ni and Al-rich B2 phase leads to strengthening and excellent strain hardening in B2s Fe-Mn-Al-Ni-C lightweight steels. However, at present, there still remain a number of fundamental challenges (mainly associated with understanding the microstructure evolution of B2 phase) and industrial challenges (associated with alloy design, thermomechanical processing, and mechanical deformation behaviour) for establishing these steels as structural materials for industrial applications (especially the automotive sector).