Passive abilities in The Secret World can potentially affect any other active ability, regardless of which cell the ability is found in or which weapons the player is currently using. It can be a good idea to learn passive abilities in cells of weapons that you may not own or use, simply because these passive abilities may synergize well with your preferred weapons or abilities.

Example:
A player using Hammers and Fists may never intend to use Shotguns, but if this player is focusing on Strike attacks from the Hammer cells they may find that the Shotgun passive ability Strike Force is useful to increase their penetration chance.