MPL and essential thrombocythemia: The incidence of classical MPL mutations in ET patients with atypical variants of driver genes was higher than ET patients without atypical variants [13.3% (2/15) vs. 0% (0/95), p = 0.02], the incidence of other classical mutated driver genes was not significantly different between the Ph‐negative MPN subgroup with atypical variants of driver genes and the subgroup without atypical variants.