As a result, clinicians are reluctant to withhold corticosteroid therapy if there is any indication of drug toxicity, further complicating the diagnosis. However, once a patient responds to corticosteroid therapy, the decision to re-institute a drug suspected of causing ILD is made on an individual basis. In this article we described an algorithm developed to assess the incidence of drugassociated ILD in Japanese patients receiving gefitinib for NSCLC. Such an algorithm, once validated, may be a useful tool in the differential diagnosis of ILD in patients with cancer and help clarify some of the apparent discrepancies in the incidence and reporting of ILD. Buzdar et al (1980) , Chang et al (1986) , Goldberg and Vannice (1995) , Rivera et al (1995) , Ramanathan and Belani (1996) , Bookman et al (1997) , Merad et al (1997) , Piccart et al (1997) , Semb et al (1998), Vander Els and Miller (1998) , Dunsford et al (1999) , Thomas et al (2000) , Fogarty et al (2001) and Read et al (2002) . a Even when paclitaxel is used in conjunction with radiotherapy. b When docetaxel is used in combination with radiotherapy or gemcitabine, the response is variable to poor. Primary biliary cirrhosis Primary biliary cirrhosis (PBC) is an immune-mediated chronic cholestatic liver disease with a slowly progressive course. Without treatment, most patients eventually develop fibrosis and cirrhosis of the liver and may need liver transplantation in the late stage of disease. PBC primarily affects women (female preponderance 9–10:1) with a prevalence of up to 1 in 1,000 women over 40 years of age. Common symptoms of the disease are fatigue and pruritus, but most patients are asymptomatic at first presentation. The diagnosis is based on sustained elevation of serum markers of cholestasis, i.e., alkaline phosphatase and gamma-glutamyl transferase, and the presence of serum antimitochondrial antibodies directed against the E2 subunit of the pyruvate dehydrogenase complex. Histologically, PBC is characterized by florid bile duct lesions with damage to biliary epithelial cells, an often dense portal inflammatory infiltrate and progressive loss of small intrahepatic bile ducts. Although the insight into pathogenetic aspects of PBC has grown enormously during the recent decade and numerous genetic, environmental, and infectious factors have been disclosed which may contribute to the development of PBC, the precise pathogenesis remains enigmatic. Ursodeoxycholic acid (UDCA) is currently the only FDA-approved medical treatment for PBC. When administered at adequate doses of 13–15 mg/kg/day, up to two out of three patients with PBC may have a normal life expectancy without additional therapeutic measures. The mode of action of UDCA is still under discussion, but stimulation of impaired hepatocellular and cholangiocellular secretion, detoxification of bile, and antiapoptotic effects may represent key mechanisms. One out of three patients does not adequately respond to UDCA therapy and may need additional medical therapy and/or liver transplantation. This review summarizes current knowledge on the clinical, diagnostic, pathogenetic, and therapeutic aspects of PBC. Primary biliary cirrhosis (PBC) [1] is an immune-mediated chronic progressive inflammatory liver disease that leads to the destruction of small interlobular bile ducts, progressive cholestasis, and, eventually, fibrosis and cirrhosis of the liver without medical treatment commonly necessitating liver transplantation. Addison and Gull [2] have first described a disease with a PBC-like picture in 1851, but the term "primary biliary cirrhosis" was coined in 1949 when a cohort of 18 patients with characteristic features of PBC was published [3] . PBC, predominantly affecting middle-aged women, is characterized by biochemical markers of cholestasis, serum antimitochondrial autoantibodies (AMA), and lymphocytic infiltration of the portal tracts of the liver [4] . Histologically, the hallmark of the disease is damage to biliary epithelial cells (BEC) and loss of small intrahepatic bile ducts accompanied by significant portal tract infiltration with CD4 and CD8 T cells, B cells, macrophages, eosinophils, and natural killer cells [5, 6] .