def build_gnab_feature_id(gene_label, genomic_build):
    """
    Creates a GNAB v2 feature identifier that will be used to fetch data to be rendered in SeqPeek.

    For more information on GNAB feature IDs, please see:
    bq_data_access/data_types/gnab.py
    bq_data_accvess/v2/gnab_data.py

    Params:
        gene_label: Gene label.
        genomic_build: "hg19" or "hg38"

    Returns: GNAB v2 feature identifier.
    """
    if genomic_build == "hg19":
        return "v2:GNAB:{gene_label}:tcga_hg19_mc3:Variant_Classification".format(gene_label=gene_label)
    elif genomic_build == "hg38":
        return "v2:GNAB:{gene_label}:tcga_hg38:Variant_Classification".format(gene_label=gene_label)