Importantly, only 12% in the variation of NPI is explained by this marker (the value of R2 from the linear regression model equal to the square of Pearson's correlation coefficient between NPI and Mcm2), a consequence of the very high levels of Mcm2 expression in higher-grade tumours (median grade 3: 96.91%; Table 1; Figure 2). The gene discussed is MCM2; the disease is neoplasm.