P66 is an outer membrane protein in Borrelia burgdorferi, the agent of Lyme disease. P66 has a role in the attachment of Borrelia burgdorferi to human cell-surface receptors [1].

1: Targeted mutation of the outer membrane protein P66 disrupts attachment of the Lyme disease agent, Borrelia burgdorferi, to integrin alphavbeta3. Coburn J, Cugini C; Proc Natl Acad Sci U S A. 2003;100:7301-7306. PMID:12748384