NRG1 and neoplasm: Meanwhile, NRG1 levels in tumor tissue also demonstrated robust predictive performance, with an AUC of 0.77 (95% CI: 0.70-0.83), sensitivity of 62.35%, and specificity of 78.29%, with a cut-off value of 143.8 ng/mL and a Youden index of 0.42 (Fig. 2 and Table 2).