Fig. 7: Anti-PD-1/PD-L1 resistance in cSCC, HNSCC, and melanoma patient samples is associated with a higher frequency of hybrid E/M and mesenchymal cancer cells.

a, b Representative immunofluorescence images of Ecad⁺, CD80⁺ or CD155⁺ (red), Vim⁺ or Ecad⁺ (green), and DAPI nuclear (blue) staining in a anti-PD-1/PD-L1 responder and non-responder cSCCs (left panel) and HNSCCs (right panel), and b anti-PD-1 non-relapsed and relapsed melanomas. Scale bar, 100 µm. c–f Percentage (mean ± SEM) of c Ecad⁻/Ecad⁺, d Vim⁻/Vim⁺, e CD80⁻/CD80⁺, and f CD155⁻/CD155⁺ cancer cells relative to total cancer cells in anti-PD-1/PD-L1 responder and non-responder cSCCs (n = 7 per group). g–j Percentage (mean ± SEM) of g Ecad⁻/Ecad⁺, h Vim⁻/Vim⁺, i CD80⁻/CD80⁺, and j CD155⁻/CD155⁺ cancer cells relative to total cancer cells in anti-PD-1/PD-L1 responder and non-responder HNSCCs (n = 6 responders, n = 13 non-responders). k–n Percentage (mean ± SEM) of k Ecad⁻/Ecad⁺, l Vim⁻/Vim⁺, m CD80⁻/CD80⁺, and n CD155⁻/CD155⁺ cancer cells relative to total cancer cells in anti-PD-1 non-relapsed and relapsed melanomas (n = 5 per group). o Forest plots showing the hazard ratios (HR; blue and red squares) ± 95% confidence intervals (CI; horizontal lines) of the association between the indicated variables and time to progression (PD) or time to relapse. Variables with HR < 1.00 represent protective factors, whereas HR > 1.00 indicates risk factors. Anti-PD-1/PD-L1 responder and non-responder cSCCs (n = 7 per group) and HNSCCs (n = 6 responders, n = 13 non-responders), and anti-PD-1 non-relapsed and relapsed melanomas (n = 5 per group). P values are determined by unpaired two-sided Student’s t-test (c–n) and two-sided Cox proportional hazards models (o). Source data are provided as a Source Data file.