Chlormethineis the prototype of alkylating agents, a group of anticancer chemotherapeutic drugs. It works by binding to DNA, crosslinking two strands and preventing cell duplication. It binds to the N7 nitrogen on the DNA base guanine. As the chemical is a blister agent, its use is strongly restricted within the Chemical Weapons Convention where it is classified as a Schedule 1 substance. Mechlorethamine belongs to the group of nitrogen mustard alkylating agents. Successful clinical use of chlormethine resulted in development of the field of anticancer chemotherapy, led by Cornelius P. Rhoads at Memorial Sloan-Kettering. The drug is a nitrogen-based analogue of mustard gas and was derived from chemical warfare research. It has been derivatized into the estrogen analogue estramustine, used to treat prostate cancer. It can also be used in chemical warfare where it has the code-name HN2.