MPL and essential thrombocythemia: To investigate whether CALR mutations were present in myeloid neoplasms, Andrikovics et al. detected JAK2, CALR, and MPL genes in 289 cases of ET and 99 cases of PMF, and they reported that in ET, 154 (53%) JAK2V617F mutation-positive, 96 (33%) CALR mutation-positive, 9 (3%) MPL mutation-positive, and 30 triple-negative (11%) cases were identified, while in PMF 56 (57%) JAK2V617F mutation-positive, 25 (25%) CALR mutation-positive, 7 (7%) MPL mutation-positive, and 11 (11%) triple-negative cases were identified [18].