Query GTEx portal for Variant's genomic position based on rsID Retrieves variant information from the GTEx portal using either an rsID or a variant ID formatted as CHR_POS_REF_ALT. If an rsID is provided, the function returns the corresponding genomic positions in both GRCh37 and GRCh38 builds. When searching for an rsID based on genomic position, the position parameter should be specified according to the GRCh38 reference genome.