IFNG and cancer: In contrast, cancer patients demonstrated a significant reduction in IFN‐γ (p < 0·0001; Figure 3C) and IL‐2 (p = 0·026; Figure 3D) SARS‐CoV‐2‐specific T‐cell responses at 3 months post‐vaccination, with several patients notable for sudden, large decreases in T‐cell responses.