Many Icom radios (e.g.7100) have a connector for automatic tuners such as the Icom AH4. The cable supplied by Icom is of a fixed length (10m) and is not shielded. Icom recommends to use shielded cable for any length greater than 10m.
The cable is nothing special and doesn't carry any RF or data signals but if run unshielded and in parallel with a [possible radiating] feed line I would assume that induced currents can cause all manner of problems.
In my particular installation ( Long wire and AH4 tuner ) the cable length exceeds 10mt so I decided to get a good quality industrial cable with braided shield. The cable was fairly easy to come by but the connector is a little bit more specialised.
I ended up finding a suitable connector on ebay. It is called "MOLEX connector set - Standard .093" 4 way (4 circuit) 1 x 4 Line" and is sold by a UK based ebay vendor. The price is very reasonable and includes freight.