PHB1 and pancreatic serous cystadenoma: In people with PSC, five out of 14 (35.7%) had autoantibodies against prohibitin 1, whereas, in people with CCA, eight out of 14 (57.1%) had autoantibodies against prohibitin 1, indicating that anti-prohibitin 1 autoantibodies are also not specific for IRC (Figure 2D).