CD34⁺ cell harvesting and PCR assessment of leukapheresis products. Yield (left y-axis) and PCR analysis (right y-axis) of the CD34⁺ cells harvested after cyclophosphamide (CTX) and cytarabine (ARAC). Each patient underwent the minimum number of procedures sufficient to complete the therapeutic program. Boxes extend from the 25th to the 75th percentile, with the horizontal line indicating the median. Whiskers extend from the largest to smallest values.