<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def from_gene_ids(cls, gene_ids: List[str]):
 """Initialize instance from gene IDs."""

        genes = [ExpGene(id_) for id_ in gene_ids]
        return cls.from_genes(genes)