BTLA and neoplasm: By multivariate analysis, ≥1 cm postoperative residual tumor [≥1 cm versus < 1 cm, HR: 2.7 (95% CI 1.6–4.7), p < 0.001] and detectable BTLA expression in cancerous tissue [detectable versus non-detectable, HR: 1.8 (95% CI 1.04–3.0), p = 0.035] were independent prognostic factors for poor OS.