PGR and breast cancer: The results of this meta-analysis showed that night shift work had a statistically significant effect on inducing receptor-positive BC, including ER+ BC (HR = 1.35, 95% CI = 1.19–1.53, p < 0.001) (I2 = 0%) (Figure 5a), PR+ BC (HR = 1.30, 95% CI = 1.09–1.54, p = 0.003) (I2 = 33.8%) (Figure 5b), and HER2+ BC (HR = 1.42, 95% CI = 1.17–1.72, p < 0.001) (I2 = 0%) (Figure 5c).