Fig. 2

Typical ALK ICC and PCR patterns. a, b, c: Specimens with a positive (score 3+) ALK ICC and ALK PCR result. Strong immunostaining was evident in 100% of tumor cells (a original magnification, 100×; b original magnification, 400×). d, e, f: Specimens with a positive (score 2+) ALK ICC and ALK PCR result. Moderate immunostaining was evident in 5% of tumor cells and faint immunostaining in 95% (d original magnification, 100×; e original magnification, 400×). g, h, i: Specimens with a false-positive (score 2+) ALK ICC result. Strong immunostaining was evident in 5% of tumor cells and faint immunostaining in 50% (g: original magnification, 100×; h: original magnification, 400×)