Description: Cytokine-like protein 1 (CYTL1) is a secreted protein. CYTL1 is expressed in CD34+ cell populations of bone marrow and cord blood which function as hematopoietic stem/progenitor cells. However, CYTL1 is not expressed in CD34- cells. Experiments with knock-out mice (Cytl1-/-) propose that CYTL1 is essential for the maintenance of cartilage homeostasis rather than cartilage and bone development, and loss of CYTL1 function is linked with experimental osteoarthritic cartilage destruction in mice.