CD4 and neoplasm: In this study, we found that the numbers of CD3+ T cells and CD4+, CD8+ subsets in different tumor regions and corresponding normal tissue of the same patient varied greatly in PTC-W and PTC-WO and moreover, the Bhattacharyya coefficient between two different samples of the same patient with PTC-WO and PTC-W varied greatly, ranging from 0.06 to 0.64.