LYPD1 and infection: Colonization is thought to be the first step for host infection (Weiser et al., 2018), and some of the key factors include: 1) pilus-1 (RrgA) and PfbA, which are implicated in first contact with the epithelium and epithelial receptors; 2) Phts, Eno and PepO, which can interact with the complement system; 3) NanA, BgaA and StrH, which function in mucus degradation; 4) PiaA, PiuA and PsaA, which harbor metal binding activity; 5) CbpE, which is related with the impairment of neutrophil activity; and 6) pneumolysin (Ply), which can damage the epithelium cells and have pro-inflammatory effects.