KRT18 and neoplasm: To evaluate the cellular distribution of K94 autoantigen, which may be a CK8/18 complex, compared with CK8 or CK18 alone, tumor cell lines (HepG2 and MCF-7) were stained with K94, anti-CK8 and anti-CK18 antibodies and then examined by using confocal microscopy (Fig. 2D).