A way of describing how you’ve responded to treatment for some types of blood cancer. In chronic myeloid leukaemia (and some types of acute leukaemia), your blood cells show a gene fault called the ‘Philadelphia chromosome’. Cytogenetic response means that treatment has reduced the number of cells with this abnormal gene. A complete cytogenetic response means that all the blood cells in your bone marrow are normal – none of them have the Philadelphia chromosome. Your doctor may also call this ‘complete cytogenetic remission’. A partial (or major) cytogenetic response means that at least two thirds of your blood cells are normal – fewer than 35 out of every 100 (35%) have the Philadelphia chromosome.