May act as a co-chaperone for HSP90AB1 (By similarity). Interacts (via TPR repeats) with HSP90AB1 (By similarity). Interacts with HSPA8, CDC6 and TBK1 (By similarity). Interacts with isoform 1 and isoform 3 of MSL1 (PubMed:17335777). Predominantly nuclear in the G1 and S phases of cell cycle and is evenly distributed between the nucleus and cytoplasm in the G2 phase (PubMed:19390865). MSL1 can promote its nuclear localization (PubMed:19390865, PubMed:24913909). Expressed at high levels in the heart, testis, kidney, brain and tongue (PubMed:19390865). Expressed at low levels in the stomach, lung and liver (PubMed:19390865). Belongs to the TTC4 family.