Question From where u4b originates and which are the roots?

[kakao1]

Hello to everyone, i already asked in another thread about R-L2. Now i'm curious about my mtdna, u4b, i did a 23andme test for see it. My mom is romanian but i saw is not so common this mtdna, can someone explain me what kind of mtdna is u4b and his story? Online i can't find a lot about this haplogroup.
Thank you so much

 

[MOESAN]

Ti begin with, do read the Eupedia 'genetics' observations about this mt haplogroup. And don't fear search on the web.

 

[kakao1]

Ti begin with, do read the Eupedia 'genetics' observations about this mt haplogroup. And don't fear search on the web.

But i saw u4b is very rare to find articles online, i can't find it so much