PR-104 is a drug from the class of hypoxia-activated prodrugs (HAPs), which is being researched as a potential anti-cancer therapeutic agent.
 It is a phosphate ester “pre-prodrug” that is rapidly converted to the HAP PR-104A in the body.
 PR-104A is in turn metabolised to reactive nitrogen mustard DNA crosslinking agents in hypoxic tissues such as found in solid tumours.
 Following initial clinical studies, it was discovered that PR-104A is also activated by the enzyme AKR1C3, independently of hypoxia.
 Hypoxia in the bone marrow of patients with leukaemia, and high activity of AKR1C3 in some leukaemia subtypes has led to interest in clinical trials of PR-104 in relapsed refractory acute leukaemias.
Clarence Henry "Happy" Day (June 14, 1901 – February 17, 1990), later known as Hap Day, was a Canadian professional hockey player who played 14 seasons in the National Hockey League for the Toronto Maple Leafs and New York Americans.
 Day enjoyed a 33-year career as a player, referee, coach and assistant general manager, 28 of which were spent in various capacities with the Maple Leafs.
 He was inducted into the Hockey Hall of Fame in 1961.
Joe's Hap'nin's is an album by trumpeter Joe Newman featuring tracks recorded in 1961 and originally released on the Swingville label.
The Hockey Hall of Fame (French: "Temple de la renommée du hockey" ) is located in Toronto, Ontario, Canada.
 Dedicated to the history of ice hockey, it is a museum and a hall of fame.
 It holds exhibits about players, teams, National Hockey League (NHL) records, memorabilia and NHL trophies, including the Stanley Cup.
 Founded in Kingston, Ontario, the Hockey Hall of Fame was established in 1943 under the leadership of James T. Sutherland.
 The first class of honoured members was inducted in 1945, before the Hall of Fame had a permanent location.
 It moved to Toronto in 1958 after the NHL withdrew its support for the International Hockey Hall of Fame in Kingston, Ontario.
 Its first permanent building opened at Exhibition Place in 1961.
 In 1993, the hall was relocated to a former Bank of Montreal building in Downtown Toronto, where it is now located.
Sin Moo Hapkido is a martial art that combines "hard" and "soft" techniques.
 From a purely technical perspective, it is very closely related to its parent art, Traditional Hapkido, though it places more emphasis on meditative, philosophical, and Ki development training.
 Hapkido is often translated as “the way of coordinating power,” which places emphasis on the physical techniques that Hapkido is often known for.
 However, the founder of Sin Moo Hapkido, Ji Han-Jae, has landed on a different understanding of the term.
 "Hap" means bringing together, gathering, or harmonizing.
 “Ki” is the energy or breath in the body that connects the mind and the body, and "Do" is the process or way this happens.
 Thus, his definition of Hapkido is, “The way of harmonizing the mind and body through the utilization of ki.”
 Sin means "higher mind or higher spirit," and "Moo" means "martial art."
The Toronto Maple Leafs are a professional ice hockey team based in Toronto, Ontario.
 The team is a member of the Atlantic Division in the Eastern Conference of the National Hockey League (NHL) and is one of the Original Six teams of the NHL.
 There have been 38 head coaches in their franchise history; one during the era of the Toronto Arenas (1917–1919), seven during the era of the Toronto St. Patricks (1919–1927) and the rest under the Toronto Maple Leafs (1927–present).
 Five Maple Leafs coaches have been inducted into the Hockey Hall of Fame as players: Dick Irvin, Joe Primeau, King Clancy, Red Kelly and Dick Duff while four others have been inducted as builders: Conn Smythe, Hap Day, Punch Imlach and Roger Neilson.
Doe Deer is a song from Toronto-based band, Crystal Castles, released on their second self-titled album, "Crystal Castles".
 The release was limited to 500 copies on 12" vinyl.
 The EP was a special release for UK's record store day.
 Prior to the release, Doe Deer was played on UK's Radio 1, and rips began to circulate around the internet.
 The 12" gained special attention because three unreleased tracks from 2004 were featured as B-sides to the lead track.
 The song was featured in the episode "Nick" of Season 5 of "Skins".
The Midnighters were an American R&B group from Detroit, Michigan.
 They were an influential group in the 1950s and early 1960s, with many R&B hit records.
 They were also notable for launching the career of lead singer Hank Ballard and the worldwide dance craze the Twist.
 Between 1953 and 1962 the Midnighters had almost two dozen hits on the U.S. Pop & R&B charts.
 Their big hits included the million-selling Billboard Top 10 pop hits "Finger Popping Time" (for which they received a 1961 Grammy Award nomination), and "Let's Go, Let's Go, Let's Go".
 The Midnighters also had 13 Top 10 R&B hits, including three that reached number 1.
 Their Top 10 R&B hits included "Work with Me, Annie", "It's Love Baby (24 Hours a Day)", "Annie Had a Baby", "The Hoochi Coochi Coo", "Teardrops on Your Letter", "Get It", "The Float" and "Nothing but Good".
 They received the Rhythm and Blues Foundation's prestigious Pioneer Award in 1992 and were inducted into the Vocal Group Hall of Fame in 1999.
 The group's lead singer, Hank Ballard, was inducted into the Rock and Roll Hall of Fame in 1990.
 The Midnighters as a "group" were inducted into the Rock and Roll Hall of Fame on April 14, 2012.
James Vincent McGarr (November 9, 1888 – July 21, 1981), nicknamed "Reds" was a Major League Baseball replacement player on May 18, 1912 when the Detroit Tigers went on strike to protest the suspension of Ty Cobb.
 Born in Philadelphia, McGarr played second base for the Tigers during the one-game strike, going went hitless in four at-bats.
 In the field, he recorded one putout, three assists, and one error.
 McGarr and fellow replacement player Dan McGarvey were friends who had also been teammates at Georgetown College.
 Other replacement players that day included Allan Travers, Hap Ward, Billy Maharg, Bill Leinhauser, Vincent Maney, and Jack Smith.
Allyson Mitchell is a Toronto-based maximalist artist, working predominantly in sculpture, installation and film.
 Her practice melds feminism and pop culture to trouble contemporary representations of women, sexuality and the body largely through the use of reclaimed textile and abandoned craft.

Question: Hap Day was inducted into what Toronto-based body in 1961?
Answer: Hockey Hall of Fame