In this study we aim to evaluate the interplay between Th1 and type 2 helper (Th2) cells cytokines in populations with a high risk of COVID-19 severe symptoms such as older individuals, males, patients with high ACE2 expression by sputum gene expression profiling (Kuo et al., 2017), in smokers by nasal epithelium gene expression profiling (Zhang et al., 2010), and in patients that died of COVID-19 by serum proteomics profiling. The gene discussed is ACE2; the disease is COVID-19.