Figure 4: Example of chest CT before and after CIK cell treatment. ((a)–(c)) Images from Unique Patient Number (UPN) 7, who was diagnosed with pulmonary metastasis after radical nephrectomy and before CIK cell treatment. ((d)–(f)) Images from the same patient after two courses of CIK cell treatment. (a) A solid space-occupying lesion (0.9 × 1.2 cm) was observed in the left lung. (b) A circular lesion (0.5 × 0.5 cm) with high density and clear boundary was observed in the right lung. The CT value was 22 Hu in the plain scan. (c) The image shows a space-occupying lesion (1.1 × 0.9 cm) with a high density signal and a clear boundary. (d) After two courses of CIK cell treatment, the tumor burden in the inferior lobe of the left lung was significantly reduced (compared to the corresponding image in (a)). (e) Chest CT indicated almost complete absence of lesions in the left lung corresponding to the image shown in (b). (f) Shrinking of lung metastatic lesions was noted.