The FHL5 antibody targets the Four and a half LIM domains protein 5 (FHL5), a member of the LIM-domain protein family involved in transcriptional regulation and cellular signaling. FHL5. also known as activator of CREM in testis (ACT), is highly expressed in germ cells, particularly in the testis, where it plays a critical role in spermatogenesis by interacting with the cAMP-responsive element modulator (CREM) to regulate post-meiotic gene expression. It is also implicated in neuronal differentiation and cancer progression. Antibodies against FHL5 are essential tools for studying its expression, localization, and function in reproductive biology, neurodevelopment, and oncology. Researchers use these antibodies in techniques like Western blotting, immunohistochemistry, and immunofluorescence to investigate FHL5's role in male infertility, germ cell tumors, and neurological disorders. Validation of FHL5 antibodies often includes testing specificity via knockout controls or recombinant protein expression. Dysregulation of FHL5 has been linked to conditions such as azoospermia and certain cancers, making it a potential biomarker or therapeutic target. Studies using FHL5 antibodies have advanced understanding of its dual roles as a transcriptional coactivator and tumor suppressor, highlighting its tissue-specific regulatory networks.