Table 3. Phenotypes of knockout mice homozygous for key genes involved in the LIF/JAK/STAT3 signalling pathway.

Gene	Major phenotype	Reference(s)
Lif	Mice grow normally to adulthood A homozygous male is fertile when mated  with a wild-type female A homozygous female is sterile when  mated with a wild-type male because  blastocysts do not implant in the  uterus. The blastocysts can implant in  the wild-type uterus Several types of blood stem/progenitor  cells are severely decreased in the  spleen and bone marrow	[129,157]
Lifr	Newborn mice die within 24 h after birth Placental architecture is disrupted Bone volume is lost by two-thirds Motor neurons are lost in the brainstem,  spinal cord and face	[158,159]
gp130	Embryos die between 12.5 dpc and term Multiple developmental failures occur in  cardiac, haemapoietic and neural  tissues Inner cell mass cells undergo apoptosis  after 6 days of diapause	[127,160,161]
Jak1	Newborn mice die within 24 h after birth Lymphocyte development is severely  impaired	[162]
Stat3	Embryos develop to the egg cylinder  stage, but die between 6.5 and 7.5 dpc	[128]