Figure 1. “Schematic representation of IFTA and IFTB complexes showing the proteins comprising each complex and their interactions. Schematic representation of IFTA (A) and IFTB (B) protein complexes showing the proteins comprising each complex and their interactions. There are variations in the specific interactions between the proteins in each complex as reported in different studies. Based on the data from protein interaction studies with visible immunoprecipitation of the IFTA complex [42], three subunits (IFT122, IFT140, and IFT144) form a stable core complex. IFT140 is proposed to interact with the IFT122–144 dimer. IFT139 and IFT122 connect through the dimer between IFT43-IFT121. In the IFTB complex, protein interactions as detected with visible immunoprecipitation and immunoblotting of human IFT proteins [8] are depicted. The core complex is formed by dimers between IFT25–27, IFT74–81, and IFT46–52. IFT22 can interact with the IFT74-IFT81 heterodimer. IFT56 (TTC26) interacts with the IFT46–52 dimer. IFT70 is proposed to interact with the IFT52-IFT88 dimer [43]. In the peripheral complex, IFT38 connects IFT20 and IFT80.