This grid-like signal is not unique to the entorhinal cortex, but can be measured during spatial navigation in prescribed parts of the medial frontal, medial parietal and lateral temporal cortices. Despite no report in rodents of grid cells outside the hippocampal formation, direct recordings during brain surgery in humans have confirmed grid-like firing patterns in some of these areas. This same network of brain regions, often referred to as the ‘default mode network’, is also regularly activated in non-spatial tasks that involve the manipulation of conceptual knowledge, such as memory, imagination, scene construction, valuation and theory of mind, and in situations when subjects must generalize learnt concepts to novel situations.
This should address any objections to my assertions that hex-grid cells are found in hub areas of the cortex.
And more support: