FOSL2, also known as fos-related antigen 2, is a protein that in humans is encoded by the FOSL2 gene. The Fos gene family consists of 4 members: FOS, FOSB, FOSL1, and FOSL2. These genes encode leucine zipper proteins that can dimerize with proteins of the JuN family, thereby forming the transcription factor complex AP-1. As such, the FOS proteins have been implicated as regulators of cell proliferation, differentiation, and transformation. Recombinant FOSL2, fused to His-tag at N-terminus, was expressed in E.coli.