Huang et al described the case of a 14-year-old girl diagnosed with ITP followed by ET 3 years later.[7] Sobas et al reported on a 45-year-old woman initially diagnosed with ITP who developed ET 21 years later.[8] A recent report from Caocci et al described the case of a 72-year-old woman diagnosed with ITP who developed ET 13 years later.[9] The patients in all these 3 cases were positive for the JAK2 V617F mutation, which was also present in the case of ET with subsequent ITP development described in this report. Here, JAK2 is linked to autoimmune thrombocytopenic purpura.