A key issue noted for First appearance of Opal Tanaka and First appearance of Charlotte Jones. X-Factor #51 was published by Marvel Comics on February 1, 1990, as part of a series that began in 1986. Louise Jones Simonson writes, and art comes from Al Milgrom, Terry Shoemaker and Tom Vincent. This 36-page issue features Cyclops, Beast, Jean Grey, Iceman and Angel, among 16 characters cataloged on VerseDB.