During the 1980s ICR scientists including Professors Hilary Calvert, and Ken Harrap and Ann Jackman developed raltitrexed (Tomudex) at the ICR, a drug active for the treatment of colon and other cancers. In 1983 research teams at the Chester Beatty Laboratory of the ICR led by Professors Chris Marshall FRS and Alan Hall FRS discovered N-RAS, one of the first human cancer transforming genes (oncogenes). Professor Alan Hall went on in 1992 to discover that the molecular mechanism for the motility behaviour of animal cells (cell to cell attachment and cell movement) is through control of cytoskeletal assembly by specific GTPase-proteins, known as Rho and Rac. The discovery is of fundamental significance in cancer research since cell motility is a key feature of cancer cell behaviour during metastasis (the spread of tumours around the human body).