Fig. (1).

Precursor lesions of pancreatic cancer: pancreatic intraepithelial neoplasia (PanINs). PanINs represent progressive stages of neoplastic growth that precede the onset of the invasive carcinoma. The progression from low-grade lesions to carcinoma (from the left to the right) is associated with an increasing number of genetic alterations. Lines represent the stage of onsent of these alterations; the thickness of the line indicates the frequency of the alteration; whereas the colour corresponds to the type of alteration (green, activation; red, loss of function).