P652: MEASURING MINIMAL RESIDUAL DISEASE BEYOND 10-4 THROUGH IGHV LEADER-BASED NEXT GENERATION SEQUENCING IMPROVES PROGNOSTIC STRATIFICATION IN CHRONIC LYMPHOCYTIC LEUKEMIA oleh P. Hengeveld, M. van der Klift, P. M. Kolijn, F. Davi, F. Kavelaars, E. de Jonge, S. Robrecht, J. Assmann, L. van der Straten, M. Ritgen, P. Westerweel, K. Fischer, V. Goede, M. Hallek, M.-D. Levin, A. Langerak