IL2 and cancer: Here, we adapted and optimized a widely utilized in vitro whole‐blood stimulation assay to determine the presence of SARS‐CoV‐2‐specific TH1‐type (IFN‐γ/IL‐2) cellular immune responses in healthy donors, to assess T‐cell responses generated from prior infection, whether the participant was symptomatic or not, and as a read‐out of vaccine immunogenicity amongst healthy donors and cancer patients.