STAT3, also known as signal transducer and activator of transcription 3, is a DNA transcription enzyme. In mammals including humans, STAT3 regulates the expression of a variety of genes that play a role in embryonic development. Specifically, STAT3 regulates cell division, cell differentiation and cell death (apoptosis). During embryonic development, STAT3 proteins are phosphorylated in a cell's cytoplasm in response to chemical growth factors. Once phosphorylated, STAT3 proteins pair up to form homodimers that act like pliers. STAT3 homodimers are transferred into the cell nucleus, where they bind to DNA to regulate embryonic development. When mutations of the STAT3 gene occur, mouse embryos cannot develop beyond embryonic day 7, the beginning of gastrulation and cell differentiation. In adults, STAT3 gene mutations are known to cause some forms of cancer. Our goal is to test potential drugs for disabling rogue STAT3 proteins using computer simulations. Here we report the process by which a STAT3 monomer (half of dimer proteins forming the pliers), was built and characterized. Then we describe the methods of setting up a dynamic simulation to test potential drugs for disabling STAT3 mutants using VMD and NAMD software.