Question: What Italian-American Mafia gangster was a cousin of Willie Moretti?

Context paragraphs:
Willie Moretti: Guarino "Willie" Moretti, also known as Willie Moore (February 24, 1894 – October 4, 1951), was a notorious underboss of the Genovese crime family and a cousin of the family boss Frank Costello.

East Harlem Purple Gang: The East Harlem Purple Gang was a semi-independent gang of Italian American hit-men and heroin dealers who, according to federal prosecutors, dominated heroin distribution in East Harlem and the Bronx during the late 1970s and early 1980s in New York City.  Though mostly independent of the Italian-American Mafia and not an official Italian-American Mafia crew, the gang was originally affiliated with and worked with the Lucchese crime family and later with the Bonanno crime family and Genovese crime family.  It developed its "closest ties" with the Genovese family, and its remnants or former members are now part of the Genovese family's 116th Street Crew.

Castellammarese War: The Castellammarese War was a bloody power struggle for control of the Italian-American Mafia, from February, 1930 to April 15, 1931, between partisans of Joe "The Boss" Masseria and those of Salvatore Maranzano.  It was so called because Maranzano was based in Castellammare del Golfo, Sicily.  Maranzano's faction won, and he declared himself "capo di tutti capi" ("boss of all bosses"), the undisputed leader of the entire Mafia.  However, he was soon murdered in turn by a faction of young upstarts led by Lucky Luciano, who established a power-sharing arrangement called "The Commission," a group of five Mafia families of equal stature, to avoid such wars in the future.

Frank Costello: Frank "the Prime Minister" Costello (born Francesco Castiglia; January 26, 1891 – February 18, 1973) was an Italian-American Mafia gangster and crime boss.  Costello rose to the top of the United States underworld, controlled a vast gambling empire across the United States, and enjoyed political influence.

Joseph Valachi: Joseph Michael "Joe Cargo" Valachi (September 22, 1904 – April 3, 1971) was an American gangster, notable as the first member of the Italian-American Mafia to publicly acknowledge its existence, and credited with popularization of the term "Cosa Nostra".

Bufalino crime family: The Bufalino crime family, also known as the Pittston crime family, Scranton Wilkes-Barre family, Northeastern Pennsylvania crime family, Northeastern Pennsylvania Mafia, or Scranton Mafia is an Italian-American Mafia crime family active in the Northeastern Pennsylvania cities of Scranton, Wilkes-Barre, and Pittston.

American Mafia: The American Mafia (commonly shortened to the Mafia or Mob) or Italian-American Mafia, is a highly organized Italian-American criminal society.  The organization is often referred to by members as Cosa Nostra (] , "our thing") and by the government as La Cosa Nostra (LCN).  The organization's name is derived from the original ""Mafia"" or "Cosa nostra", the Sicilian Mafia, and it originally emerged as an offshoot of the Sicilian Mafia; however, the organization eventually encompassed or absorbed other Italian-American gangsters and Italian-American crime groups (such as the American Camorra) living in the United States and Canada that are not of Sicilian origin.  It is often referred to as the Italian Mafia or Italian Mob, though these terms may also apply to the separate yet related organized crime groups in Italy.

Bugsy Siegel: Benjamin "Bugsy" Siegel (February 28, 1906 – June 20, 1947) was a Jewish American mobster.  Siegel was known as one of the most "infamous and feared gangsters of his day".  Described as handsome and charismatic, he became one of the first front-page celebrity gangsters.  He was also a driving force behind the development of the Las Vegas Strip.  Siegel was not only influential within the Jewish mob but, like his friend and fellow gangster Meyer Lansky, he also held significant influence within the Italian-American Mafia and the largely Italian-Jewish National Crime Syndicate.

Patriarca crime family: The Patriarca crime family (pronounced ] ) is also known as the New England crime family, the Providence crime family, the Boston crime family, the Boston Mafia, the Providence Mafia, the New England Mafia, or The Office and is an Italian-American Mafia crime family based in New England.  The crime family has two distinct factions, one active in Providence, Rhode Island and the other in Boston, Massachusetts.

Caporegime: A caporegime or capodecina, usually shortened to just a capo, is a rank used in the Mafia (both the Sicilian Mafia and Italian-American Mafia) for a "made member" of the crime family who heads a "crew" of soldiers and has major social status and influence in the organization.  Caporegime is an Italian word, which is used to signify the head of a family in Sicily, but has now come to mean a ranking member, similar to captain or senior sergeant in a military unit.  In general, the term indicates the head of a branch of an organized crime syndicate who commands a crew of soldiers and reports directly to the Don (Boss) or an Underboss or Streetboss.

Supporting paragraphs: Willie Moretti Frank Costello
Answer: Frank Costello