Subject invention belongs to the treatment of the lump and cancerous tissue and prevention of tumour generation and malignant transformation by the modulation of STAT3 signal transductions. Subject invention is related to pharmaceutical compositions, includes one or more withacnistin compounds or a pharmaceutically acceptable salt or derivatives thereof. In one embodiment, it includes withacnistin that subject invention, which is related to a composition, and-the 2 of 3 methoxyl groups, the mixture or a kind of salt or foregoing. of 3 dihydrowithacnistin and 3 kinds of ethoxy -2,3 dihydrowithacnistinIn any one derivative, another aspect of the present invention is related to method, it inhibits through management one or more withacnistin compounds, or one pharmaceutically acceptable salt or derivative a lump growth, to a patient, wherein lump is characterized in that the composing type activation in STAT3 signal transductions path. The present invention further belongs to method mitigation STAT3 signal pathways and is used in vitro or in vivo one or more withacnistin compounds or a pharmaceutically acceptable salt or derivatives thereof.
