showed a trendP = 0.061
Multivariate analysis to evaluate the effect of mutation ( CALR vs JAK2 ) on the slope of mutant burden in not treated pts with a positive slope adjusting for diagnosis (ET vs PMF) showed a trend toward a higher increase of mutant burden in CALR vs JAK2 (β = 0.19, P = 0.061) with no difference between diagnosis ( P = 0.419).