The possible adverse effects of dispersing toxic anti-tumor agents in the circulatory system during conventional cancer treatment prompt us to consider the need of an alternative cancer therapeutic method. In an effort to combat colorectal carcinoma, we aim to use genetically modified Bacillus subtilis to execute targeted drug delivery to cancer cells in the lower digestive tract, offering the advantage of generating minimal negative effects on normal colon epithelial cells. Targeting is achieved by expressing RPMrel, a colon tumor specific binding peptide, on the cell wall of Bacillus subtilis using a LytC cell wall binding system. Upon successful binding, the anti-tumor cytokine bone morphogenetic protein 2(BMP-2), can be synthesized and secreted from the bacterial cells with the help of a signalling peptide fused to the protein. Minimization of the harmful effect of BMP2 overdose is made possible by introducing two regulatory systems: xylose-inducible system and ydcE/ydcD toxin-antitoxin system, which serve to control the timing and amount of BMP2 release.