Detection of the neoplastic TCR-β clonotypes in the peripheral blood. The sequences of the TCR-β clonotypes in the blood that matched any of the top 10 neoplastic TCR-β clonotypes identified in the corresponding skin sample were identified to detect the neoplastic clonotypes in the circulation. The number and frequency of those shared neoplastic clonotypes are shown separately for the 3 groups of patients as defined in Figure 1. Nineteen patients with a single biopsy specimen (A-B); patients who had multiple skin biopsies (C-F), of whom in 7 patients, the biopsy specimens were obtained at a single time point (C-D); and 3 patients who were sampled longitudinally (E-F). In panels B, D, and F, the first-ranking shared clonotype in the skin is indicated in red, and the subsequent shared clonotypes are color-coded as indicated in the legend. The nonoverlapping clonotypes are indicated in gray. P, plaque; PB, peripheral blood; T, tumor.