Summary of the overall effects of particular second kinase inhibitors on the development and regression of BCR-ABL kinase domain mutations. After treatment with second TKI, 2 patients treated with nilotinib lost baseline mutations [(M35IT) and (G250E + F317L)] but acquired new mutations [(F359V) and (T315I + Y253H)], respectively; 1 patient treated with dasatinib lost baseline mutations (E459G + M351T + G250E) and acquired a new mutation (F317L). After treatment with a third TKI, 2 patients treated with dasatinib lost baseline mutations [(F311I + E453K) and (F359V)] but acquired new mutations [(F317L) and (V299L)], respectively.