Since S. pneumoniae was found to co-localize with pIgR immunoreactivity in endothelial cells in the blood-brain barrier, the effects of pIgR deficiency and pIgR_Ab were attributed to a blockade of pneumococcal binding to pIgR expressed by endothelial cells and a resultant inhibition of pneumococcal infection of these cells (10). Here, PIGR is linked to pneumococcal infection.