TNF and Crouzon syndrome-acanthosis nigricans syndrome: As expected, the levels of both IFN-γ and TNF-α produced by total NK cells were higher in patients who were classified as chronically active (mean values, 46.2 for IFN-γ; and 62.9 for TNF-α) compared with the CAN cohort (28.3 for IFN-γ (p = 0.0023) or 33.2 for TNF-α (p < 0.0001)).