May act as a co-chaperone for HSP90AB1 (PubMed:18320024). Promotes Sendai virus (SeV)-induced host cell innate immune responses (PubMed:29251827). Interacts (via TPR repeats) with HSP90AB1 (PubMed:18320024). Interacts with HSPA8 and CDC6 (PubMed:18320024). Interacts with TBK1 (PubMed:29251827). Interacts with MSL1 (By similarity). Predominantly nuclear in the G1 and S phases of cell cycle and is evenly distributed between the nucleus and cytoplasm in the G2 phase (By similarity). MSL1 can promote its nuclear localization (By similarity). Highly expressed in proliferating tissue and tumor cell lines but not in normal cell lines. Belongs to the TTC4 family.