ATEEZ have become ambassadors for the 'Polished Man' campaign.
'Polished Man' challenges men (and women) to paint one nail and raise funds & awareness for children affected by violence globally. Hongjoong is already well-known to have one polished nail in participation of the campaign. Recently, the other members also started painting one nail and it looks like they're now one of the official ambassadors.
You can check out the campaign here.