Escaping parenthesis in regular expressions....

  How does one escape parenthesis in a regular expression in Postgres?

  An example is:

select * from subcategories where subcategory ~* '401(k)';

Which does not work.  I've tried:

select * from subcategories where subcategory ~* '401\(k\)';

That still didn't work.  Any advice would be much appreciated.  BTW,

select * from subcategories where subcategory  =  '401(k)';

does work. ; )

steve