Answer:
Tunneling nanotubes.
Explanation:
Tunneling nanotubes refer to certain very thin and elongated tubules that emerge from the membrane of a cell and allows it to connect and communicate with other neighboring cells over relatively long distances. Because of their very small size, tunneling nanotubes were only discovered until 1999, and their role in cell communication is still not fully understood. It is known that they're capable of transmitting and conducting cell-surface proteins, cytoplasmic vesicles and calcium signals between cells. However, they can also act as vectors for viruses such as HIV.
