1. human thyroid primary cells Thyroid cells are isolated from human thyroid tissue which can produce thyroid hormones. As an endocrine gland, thyroid plays an important role in metabolism regulation and growing development. Abnormal thyroid hormone production results in hyperthyroidism, hypothyroidism, and thyroiditis. Creative Bioarray can offer human primary thyroid fibroblasts, which are characterized by their spindle morphology and positive for fibronectin by immunofluorescent test.