PTGS2 and Miyoshi myopathy: Exposure of a monocyte-macrophage (J774) cell line to an asbestos-like amphibole fiber known as fluoro-edenite induced a significant increase in PTGS2 expression [30], and immunohistochemical characterization of human MM samples demonstrated that PTGS2 was highly expressed in these tissues, but not in nonreactive mesothelial tissues from the same individuals [31].