Accounts of cancer have been around for many centuries. The ‘War on Cancer’ has officially been going on since 1971 with the passing of the National Cancer Act. The aim of this was to understand more about the behavior and biology of cancer in addition to the development of efficacious drug therapies. Although such therapies have been discovered and developed, the precision of ‘traditional chemotherapeutics’ have shown not to be as precise as desired. For example, these drugs aim to kill cancer cells that are dividing at a higher rate than normal relative noncancerous cells. However, noncancerous cells that require to divide rapidly (gut, epidermis, keratinocytes of the scalp) are prone to these traditional chemotherapies and as such patients experience undesirable side effects. The aim of this paper is to address the development of a novel cellular-based cancer therapy called CAR T-cell therapy. The structure of such a therapy enables greater precision than traditional chemotherapies and potentially greater efficacy than standard cancer immunotherapy drugs. The structure, function, and cytotoxic mechanisms of CAR T-cells will be addressed along with landmark clinical trials that have lead to the US FDA approval of two CAR T-cell therapies. In addition to successes, consequences of this therapy will be discussed involving toxicities, economic costs, and hardships against solid tumors.