Thymopentin is a member of the LEM family. Thymopentin is expressed in many tissues, highly in the adult thymus and fetal liver. The N-terminal contains two structurally independent domains, LEM domain and LEM-like domain. The C-terminal domain forms a four-stranded coiled coil. Thymopentin may be involved in the structural organization of the nucleus and in the post-mitotic nuclear assembly. It is associated with T-cell development and function. Meantime, Thymopentin plays an important role, together with LMNA, in the nuclear anchorage of RB1. Thymopoietin is participated in the induction of CD90 in the thymus.