Professor Partha Pratim Majumdar, who heads the unit and is chief programme officer of National Institute of Biomedical Genomics, said it is a major development for the identification of causes and treatment of various types of cancer.

Scientists at the institute said they are well aware of the genetic predisposition to cancer but did not know as to what kind of genetic changes occur in the cells.

Professor Majumdar said some cancerous cells are inherited and others are acquired.

Although the inherited changes have been traced out earlier, the researchers have now come out with details of acquired changes.

Cancer scientists at the ISI say their focus of interest is oral cancer, which is most common India.

India is a member of the global consortium International Cancer Genome Consortium (ICGC), which organises and coordinates research on genomic changes in cancers. Prof Majumdar is the Indian representative at the consortium.