<p>TCGA pan-cancer survival forest plot: SLC6A4 low versus high.</p>

Pooled HR = 1.04 (95% CI [0.94, 1.15]; <i>p</i> = 0.42; I² = 13.0%). SLC6A4 expression was not independently prognostic, consistent with TCGA representing a pre-immunotherapy era cohort where the immune desert phenotype driven by SLC6A4 would not directly affect survival in the absence of immune checkpoint inhibitors.

PAAD (HR 1.70; 95% CI [1.12, 2.57]; <i>p</i> = 0.011) was the only individually significant cancer type; higher SLC6A4 was associated with better survival. Per-cancer hazard ratios and <i>p</i> values are from Cox proportional hazards models; the pooled estimate, its <i>p</i> value, and I² are from a random-effects meta-analysis (restricted maximum likelihood, Hartung–Knapp confidence interval); the heterogeneity <i>p</i> value printed in the figure is from Cochran Q.</p> <p>(TIF)</p>