Getting info on blocks adjacent to the targeted block

So.. I know how to get the block info for a block I'm currently looking at, or interacting with.  Let's use right clicking, for this example.

    @SubscribeEvent
    public void onBlockInteract(PlayerInteractEvent.RightClickBlock event)
    {
        Minecraft mc = Minecraft.getMinecraft();
        EntityPlayer player = event.getEntityPlayer();
        BlockPos pos = mc.objectMouseOver.getBlockPos();
        Block block = player.getEntityWorld().getBlockState(pos).getBlock();  //Based on pos, block is the block the player is targeting
        IBlockState state = player.getEntityWorld().getBlockState(pos);

    }

Now what I'd like to know is, how do you get Block adjacent to the one being right clicked?  Let's say.. the block north, south, east or west of the target block.