In conclusion, i(17q) presence in CLL cases with TP53 deletion should be considered as a potentially adverse marker for more aggressive course of the disease than monosomy of 17p13.1 alone; it needs to be kept in mind that MLPA alone may be not sufficient to pick up all corresponding cases and a combination with iFISH may be considered additionally. The gene discussed is TP53; the disease is B-cell chronic lymphocytic leukemia.