The dispersal of toxic anti-tumor chemicals in the circulatory system during conventional cancer treatment prompts us to consider the need of alternative cancer therapies. In an effort to combat with colorectal carcinoma, we aim to use genetically modified Bacillus subtilis to execute targeted drug delivery to cancer cells in the digestive tract, offering an advantage of generating minimal adverse effect on normal colon epithelial cells. Targeting is achieved by expressing RPMrel, a colon tumor specific binding peptide, on the cell wall using a LytC cell wall binding system. The anti-tumor cytokine, bone morphogenetic protein 2 (BMP-2), is synthesized and secreted out from the bacteria with the help of a signaling peptide fused to the protein. To control the timing and amount of BMP2 release, two regulatory systems, xylose-inducible system and ydcE/ydcD toxin-antitoxin system are introduced to minimize the harmful effect from BMP2 overdose.