Sales Person mobile phone visible in UI

I came across a really strange one this week. On the Sales Person, a standard field is available for the mobile phone number. However, this field is not visible in Marketo's UI. So even if there is data being sent there from CRM you cannot leverage this data via a token to communicate this number to customers or leverage alerts via SMS/Whatsapp to the sales person's phone. Having the field currently holds no value and any data only takes up server space.

It would be great if the field could be made available on the UI.