Unfortunately, a humanized IgG4 monoclonal antibody against LOXL2, Simtuzumab® (Gilead Sciences SA), has failed so far to achieve a significant clinical benefit in patients with idiopathic pulmonary fibrosis (54), NASH (55, 56), or primary sclerosing cholangitis (57). Here, LOXL2 is linked to pulmonary fibrosis.