The invention relates to proteins comprising Interleukin 11 (IL-11) (including, but not limited to, fragments and variants thereof), which exhibit thrombopoietic or anti-inflammatory properties, fused to albumin (including, but not limited to, fragments or variants of albumin). These fusion proteins are herein collectively referred to as “albumin fusion proteins of the invention”. These fusion proteins exhibit extended shelf-life and/or pharmacokinetic properties and/or extended or therapeutic activity. The invention encompasses therapeutic albumin fusion proteins, compositions, pharmaceutical compositions, formulations and kits. The invention also encompasses nucleic acid molecules encoding the albumin fusion proteins of the invention, as well as vectors containing these nucleic acids, host cells transformed with these nucleic acids and vectors, and methods of making the albumin fusion proteins of the invention using these nucleic acids, vectors, and/or host cells. The invention also relates to compositions and methods for treatment or prophylaxis of thrombocytopenia or inflammatory diseases.