In other words, it is composed of multiple regression coefficients estimated by the multivariate S-LDSC model. The distinction between S0 and Sτ directly parallels the distinction made in univariate S-LDSC32 between overall heritability explained by an annotation and the incremental contribution of an annotation to heritability beyond all other annotations considered. Note that the estimates required to populate elements of an overall genome-wide S matrix can be produced either from the zero-order annotation that includes all SNPs or by aggregating parameters corresponding to each annotation from the multivariate S-LDSC model used to estimate Sτ.
