KLIP1(KILLER LINEAGE PROTEIN 1), also known as YIPF3. The KL1P1 gene is mapped to chromosome 6p21.1. The KLIP1 gene contains 9 exons and spans about 5 kb. And KLIP1 also contains an N-terminal signal sequence, followed by an extracellular domain, 5 transmembrane regions, and a cytoplasmic C-terminal sequence. KLIP1 expression closely correlated with hematopoietic activity in both intra- and extra-embryonic hematopoietic sites. In day 30/32 human embryo sections, KLIP1 protein expression was restricted to circulating hematopoietic cells at hematopoiesis sites. Western blot analysis of fetal liver extracts and in vitro translated KLIP1 cDNA detected the KLIP1 protein at an apparent molecular mass of 37 kD. Phylogenetic analysis indicated that KLIP1 is highly conserved.