SNHG15 and digestive system cancer: A strong correlation was revealed between increasing expression of SNHG15 and poor OS in digestive system cancers (HR = 2.57, 95% CI, 1.77–3.74; P<0.0001), respiratory system cancers (HR = 2.16, 95% CI, 1.44–3.24; P=0.0002), cancers with less than 60 patients (HR = 2.04, 95% CI, 1.48–3.06; P<0.00001), more than 60 patients (HR = 2.04, 95% CI, 1.26–3.31; P=0.004), HRs extracted directly from studies (HR = 2.24, 95% CI, 1.39–3.59; P=0.009) or indirectly from the Kaplan–Meier curve (HR = 1.86, 95% CI, 1.24–2.81; P=0.003) (Figure 2A and Table 3).