I'm trying to get the following to return "pfam03571" from the XML structure.
Cases[
XMLElement[
"myelem", {}, {XMLElement[
"INSDQualifier_value", {}, {"Peptidase family M49; pfam03571"}]}],
XMLElement[_, {}, {___~~x:RegularExpression["pfam\\d+"]~~___}]:>x,
Infinity]
This doesn't work. Is this possible without extracting all XMLElement values (I don't know the element tag name) and using StringCases?
