HEYL and susceptibility to pneumonia measurement: Statistical analysis of our data showed that partial-methylated of HeyL promoter increased the risk of severe pneumonia 5.66 times (P = 0.0513), fever 10 times (P = 0.0246), anosmia/ageusia 7.5 times (P = 0.0278), and dry cough 10.55 times (P = 0.0140).