HTR1B and myeloproliferative neoplasm: At post‐hoc Dunn's multiple comparisons test thrombotic MPN patients exhibited significantly higher HTR1B relative expression levels compared to non‐MPN thrombotic patients (median log10 fold change 3.055 vs. 0.5608, p = 0.0253), while the transcript expression levels were not significantly different between non‐MPN thrombotic patients and control group (median log10 fold change 0.5608 vs. 0.08451, p = 0.9999) (Figure 2C).