Genome‐wide association study had identified BTNL‐2, a butyrophilin/B7‐like molecule, a purported negative costimulatory molecule for T‐cell proliferation, as a potential susceptibility factor 12 but the function of BTNL‐2 in sarcoidosis is poorly understood and little functional work has been done to support this hypothesis. This evidence concerns the gene BTNL2 and sarcoidosis.