Cancer is not just one disease but a group of diseases involving abnormal cell growth and metastasis of such cells to other body parts. There are also several types of cancers, each with its own distinctive characteristics and stages that may require different treatment or targeted drug delivery approaches. Yet, even these treatments have their own advantages and disadvantages. Thus, since the discovery of cancer, researchers have constantly been developing new and innovative cancer treatments, including chemotactic drug delivery. For example, and as mentioned earlier in this article, researchers have sought to use microdroplets, protocells, and biological and bio-hybrid drug carriers to deliver drugs to cancer cells in a more effective manner, while reducing unwanted side effects. In fact, the justification for using such systems, guided by chemotaxis, is that the environment inside a tumor has a higher resting temperature, higher peroxide concentration, lower pH, and a lower oxygen concentration than its surrounding tissue. With these unique conditions, researchers can exploit chemotactic drug delivery to target tumor cells directly, avoiding healthy tissues, reducing toxicity, improving drug efficacy, and decreasing drug dosage.