Immunogen sequence: HSTLKPAAHL IGDPSKQNSL LWRANTDRAF LQDGFSLSNN SLLVPTSGIY FVYSQVVFSG KAYSPKATSS PLYLAHEVQL FSSQYPFHVP LLSSQKMVYP GLQEPWLHSM YHGAAFQLTQ GDQLSTHTDG IPHLVLSP. TNF beta, a member of the tumor necrosis factor family, is a cytokine produced by