seromucus secreting cell acinar cell of salivary gland seromucous acinar cell of salivary gland 2025-08-06T11:26:37Z An acinar cell of the salivary gland, with a hybrid seromucous phenotype, co-expressing serous and mucous markers and producing a mixed secretion of enzymes-containing serous fluid and mucins essential for lubrication, digestion, and antimicrobial defense. Predominant in the submandibular glands of humans and mice, its differentiation and secretory gene expression are regulated by FGFR2b–MAPK signaling, driven by paracrine FGF7 from adjacent myoepithelial cells, which provides a key niche signal for seromucous identity.