“…Serous cells secrete zymogens, enzymes, and antibodies to defend airways against bacteria and viruses; these include lysozyme, lactoferrin, zymogen granule protein, and bactericidal permeability‐increasing protein. We identified a large cluster of serous cells characterized by high expression of LYZ , STATH , LTF, ZG16B , BPIFA1, BPIFB1 , S100A1 , and PIP ( Figure 2 ) 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 ; the latter 2 play a role in the regulation of calcium content in the secretions. 11 , 13 , 25 …”