Cancers ultimately develop due to aberrations that involve proteins and modify their effects. Given that the structures of many proteinsinvolved in cancer pathogenesis are known, numerous studies have employed MD simulations in cancer research. In this chapter, somecauses and treatments for cancer are briefly introduced. Thereafter, systems where cancer development or therapy have been studied byMD simulations are described, focusing on contemporary subjects of interest. These include tumor cell metabolism, RAS proteins,driver mutations, allosteric inhibitors, kinetics of drug binding, activation of protein kinases and anticancer drug delivery. While notproviding a complete picture of the fields, these subjects allow the reader to understand what sorts of systems are studied, how, andwhich conclusions can be made with the help of MD simulations. This might help the interested reader to utilize such simulations forfurther studies in the field.