Merges and single-color separations of paired immunofluorescence staining for IgD (green) and CCR10 (red). The 3 depicted samples represent (A) adenoids (extrafollicular area), (B) salivary gland (normal parotid), and (C) nasal mucosa (glandular area). Many cells with variable peripheral CCR10 expression are seen, being particularly intense when showing a large plasmablast appearance. Some of these contain cytoplasmic IgD (arrows), but occasional clearly mature IgD⁺ plasma cells are completely negative for CCR10 (arrowheads). Magnification ×100.