In case I search for "Ca2+" or "Sa2+" see PD map here,
in the search results there is "Compartment: neuron", not Ca2+ related entity. It looks like the search query takes also into searching the compartments aliases ("ca", "sa"). Is it correct behaviour? If it is let's add the warning dialog suggesting to narrow search results by adding prefix ION, molecule or RNA (e.g. ION:Ca2+) or informing that there might appear additional outcomes (like "Compartment: neuron").