According to a study published in the journal Cell, scientists have identified an enzyme that is crucial for turning breast tissue into tumours. The Institute of Cancer Research says, blocking the enzyme lysyl oxidase (LOX) reduced the size and frequency of tumours in mice. They say LOX stiffens collagen, a major component of the supportive tissue in the breast. A cancer charity said the study added to knowledge about how tumours develop. The supportive tissue surrounding cancer cells is shaped differently to healthy tissue as well as being stiffer and more fibrous. These properties have helped doctors to detect breast cancers, but until now scientists have not known what was causing these changes. <br/>