Table 4.

Summary of studies examining Stat3 expression in IBD

Study	Number of Patients	Analysis	Major Findings
Lovato et al., 2003 [22]	7 CD pts 7 healthy patients	Immunoblot analysis for Stat3 and Stat4 in intestinal immune cells and/or peripheral immune cells	Stat3 and Stat4 are constitutively activated in CD pts
Mudter et al., 2005 [19]	30 IBD patients 6 healthy patients	Intracellular staining for Stats on isolated lamina propria CD4 cells and IHC	pStat3: markedly increased in inactive IBD vs control pts. pStat1 and pStat6: no difference between active IBD pts and control
Carey et al.,2008 [21]	17 CD patients 26 CD-treated patients 11 UC patients 20 healthy patients	Serum cytokine analysis pStat3 in peripheral blood leukocytes pStat3 IHC Microarray analysis	Stat3 + peripheral granulocytes, lamina propria immune cells and colonic epithelial cells correlated with disease activity Circulating IL6 is increased in IBD patients
Li et al., 2010 [21]	73 UC pts (inactive, chronic active, LGD, HGD, CAC) 14 Sporadic colorectal cancer pts	IHC for pStat3, IL6 and SOCS3	active UC pts: increased pStat3 and IL6 as compared to pts with inactive disease. SOCS3 elevated. HGD and CAC pts: increased Stat3 and IL6 as compared to controls, decreased SOCS3

Abbreviations: IBD, inflammatory bowel disease; LGD, low-grade dysplasia, HGD, high-grade dysplasia, CAC, colitis-associated cancer, IHC, immunohisotchemistry, SOCS3, suppressor of cytokine signalling 3(a target of the pStat3 pathway which regulates negative feedback to Stat and cytokine signaling).