Immunophenotyping of NK cells
APC
PB samples were obtained before stopping TKI and then at months 3, 12 and at any time when MMR was lost, as shown in Organization of the study and characteristics of the patients. The following anti–human monoclonal antibodies (mAbs) were used in this part of the study: BV421 anti-CD56 (NCAM16.2), APC-H7 anti-CD3 (SK7), APC anti-IgG1 (X-40, MOPC-21), PE anti-IgG2b (MPC-11), PE anti-IgG2a (X-39), BB515 anti-NKp44 (p44-8), V500 anti-CD16 (3G8), PE-Cy7 anti-CD25 (M-A251), APC anti-NKG2D (1D11), FITC anti-CD57 (NK-1), APC anti-PD-1 (MIH4), PE anti-CD158a (HP-3E4), PE anti-CD158b (CH-L), PE anti-NKp30 (p30-15), PE-Cy7 anti-NKp46 (9-E2), all from BD Biosciences (San Jose, CA, USA); PE anti-NKG2A (131411; R&D Systems) and AF647 anti-NKG2C (134591; R&D Systems). PBMC were stained for 30 min at 4°C, washed twice with staining buffer (PBS with 2% FBS) and acquired in a FACSCanto II flow cytometer (BD). Flow cytometric data were analyzed using FlowJo software (Tree Star).