JAK2 and myeloproliferative neoplasm: For example, Ortmann et al. described a predictive effect of TET2 mutations to treatment with ruxolitinib in MPN patients, depending on the sequence of their appearance compared to the driver JAK2. For patients acquiring the JAK2 mutation before TET2 (“TET2-second”), a higher probability of a favorable ruxolitinib response compared to “TET2-first” patients was noticed.