FUNCTION: Atypical homeodomain protein which does not bind DNA and is required to modulate cardiac growth and development. May act via an interaction with SRF, leading to modulate the expression of SRF- dependent cardiac-specific genes and cardiac development (PubMed:12297045). May act as a co-chaperone for HSPA1A and HSPA1B chaperone proteins and assist in chaperone-mediated protein refolding (By similarity). {ECO:0000250|UniProtKB:Q9BPY8, ECO:0000269|PubMed:12297045}. SUBCELLULAR LOCATION: Nucleus {ECO:0000250|UniProtKB:Q8R1H0}. Cytoplasm {ECO:0000250|UniProtKB:Q8R1H0}. |