A CD68/CD163 ratio > 1.63 correlated with shorter thrombosis-free survival (41.4 vs. 68.2 months; p = 0.001; hazard ratio [HR] 2.45, 95% confidence interval [CI] 1.45–4.14) and secondary myelofibrosis progression-free survival (48.3 vs. 79.0 months; p = 0.001; HR 2.67, 95% CI 1.55–4.60). The gene discussed is CD163; the disease is deep vein thrombosis.