In pediatric CML, the importance of the 3-month milestone has likewise been observed: a French multicenter study first showed that children with BCR::ABL1 ≤ 10% at 3 months had higher 12-month CCyR/MMR rates and improved PFS compared to those >10% [12]. The gene discussed is BCR; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.