Complete telomere loss in CLL patients. (A) XpYp and (B) 17p STELA LOH is detected when there is a differential number of amplifiable molecules between the 2 telomeres; the percentage of telomeric molecules at 17p relative to that detected at the XpYp telomere is shown below the 17p STELA blot. Two persons show almost complete LOH at 17p (#35 and #21) and one (#30) shows loss of one XpYp allele, highlighted in red.