(A) Correlation between XBP1 and 13 inhibitory immune checkpoints. (B) Correlation between XBP1 and four immune checkpoints (PD-L1, CTLA-4, PD-1 and LAG-3) based on GETx dataset. (C) Correlation between XBP1 and four immune checkpoints (PD-L1, CTLA-4, PD-1 and LAG-3) based on TCGA dataset. The dots represent cancer types or tissue types, red dots represent BC or breast tissue. The Y-axis represents the Pearson correlation, while the X-axis represents -log₁₀P. (D) Differences in the enrichment scores of immunotherapy-predicted pathways between high and low XBP1 groups.