Transcription and expression of Stx11 in cytotoxic lymphocytes. NK cells or CD8⁺ T cells were isolated from PBMCs by negative selection. (A) cDNA was prepared from cells and cell lines. RT-PCR was performed with gene-specific primers as indicated. (B) Stx11 expression relative to actin control was measured by immunoblotting in lysates derived from purified cell CD8⁺ T-cell or NK-cell populations, as well as the NK-cell line NK92. Arrowheads indicate bands corresponding to actin and Stx11 immunoreactivity.