The genes induced in NK cells in co-culture with CML cells that were attributed with co-stimulatory functions like TNFRSF9/4-1BB (Padj = 0.0026, Bonferroni corrected t-test), TNFRSF18/GITR (Padj = 6.05 × 10−11), and TNFRSF4/OX-40 (Padj = 0.0038) were significantly upregulated in active NK cells in patients with TFR in comparison to on TKI and relapse samples (all Padj < 0.01, Bonferroni corrected t-test). The gene discussed is TNFRSF9; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.