STAT3-IN-38 (Compound 4m) is an inhibitor of STAT3 (K D of rhSTAT3: 45.33 µM). STAT3-IN-38 binds to the SH2 domain of STAT3 protein and suppresses the STAT3’s phosphorylation at site pTyr705 as well as its downstream genes ( Survivin and Mcl-1 ). STAT3-IN-38 could block cell-cycle and induce Apoptosis in colorectal cancer cells.