NRG1 and prostate cancer: Furthermore, a meta-analysis of 16 publicly available prostate cancer gene expression datasets, comprising a total of 1,081 prostate cancer cases and 294 adjacent normal tissues revealed downregulated NRG1 expression in prostate cancer compared with that of adjacent normal tissues (standardized mean difference = −0.73, 95% CI = −0.99 to −0.48, p < 0.001; Figure 5).