Cyberpunk RED – Increase STATS with improvement points

Just checking the new Cyberpunk RED rules, and looking the improvement points section (page 411) it says the way to improve your character skills (normal and x2) and your Role Ability Rank, but, since you are limited to a maximum of 8 in your stats (INT,REF,DEX…) I suppossed that there will be a cost for raising your base STATS, but can’t find any mention.

I don’t know if I missed something, its only intented to achieve such levels with cyberimplants (I doubt it) or another reason.

Maybe a STAT has the same cost as Role Ability Rank and is mentioned somewhere?