5-Hydroxymethyl cytosine (5-hmC) is increasingly being recognized as a base in its own right rather than an intermediate of methyl cytosine (5-mC) on its way to demethylation. 5-hmC, touted as the sixth base, is produced by ten-eleven translocation (TET) enzymes as they oxidize 5-mC.

What is second base for a girl?

--Second Base- Variously this meant tongue kissing, breast feeling, or outside the clothes genital contact.