Chemotherapy works by killing fast-dividing cells.

The problem is that it cannot tell a tumour from healthy tissue, so it damages both, which is why the treatment takes such a toll on cancer patients.

A second problem compounds the first.

Cancer stem cells, a small population within a tumour, tend to survive chemotherapy and are associated with the disease returning later.

, a biotech company in Bhubaneswar, is working on both.