PECAM1 and infection: Immunological similarities of patient chimeras and patient chimera substitutes have been demonstrated by (i) impaired production of human skin antimicrobial peptides, (ii) increased susceptibility to P. aeruginosa i.d. infection, and (iii) remarkable production of human CCL2 and IL-10 (effector factors for patient CD31+ IMC to inhibit antimicrobial peptide production).