Here's everything you need to know about Mnuchin:
Name: Steven Terner Mnuchin (pronounced Min-OOCH-in)
Age: 53 (born Dec. 21, 1962)
Birthplace: New York City. Mnuchin comes from an influential New York family; his father, Robert Mnuchin, was a partner at Goldman Sachs and opened the Mnuchin Gallery on the Upper East Side.
Education: Yale University
What he did before his nomination: Steve Mnuchin was a co-founder, a co-CEO and the chairman of Dune Capital Management. He was a member of Trump's transition team executive committee.
Relationship with Trump
ABC News reached out to Mnuchin via Dune Capital Management about this lawsuit but did not receive a response.
Positions on financial regulation
As treasury secretary, Mnuchin could be influential in the push — promoted by the Trump team — to alter the Dodd-Frank Wall Street regulations.
In a July interview with CNBC, Mnuchin said Dodd-Frank, passed in 2010, needs to be re-examined. "We're not taking a position on whether we support that or don't support it. We're saying a lot of things need to be looked at. We think Dodd-Frank needs to be looked at. Obviously there is an important concern of protecting depositors."
Two groups in California, the California Reinvestment Coalition and Fair Housing Advocates of Northern California, recently filed a complaint with the Department of Housing and Urban Development against the CIT Group, alleging that it, as the successor to OneWest, failed to open a significant number of branches in minority neighborhoods and provide adequate loans in Southern California, including Los Angeles.
Mnuchin's mother invested with Bernie Madoff. She died in 2005 and left her sons $5 million. Securities Investor Protection Act Administrator Irving Picard sued them, claiming that $3 million of the money was stolen profits. The lawsuit was ultimately dropped.
In an interview with Bloomberg Businessweek, Mnuchin said of the lawsuit, "This was one of hundreds of cases that there was a decision on. There is nothing special about this case."
ABC News reached out to Mnuchin via Dune Capital Management about this lawsuit as well and did not receive a response.
History of Democratic donations:
Although Mnuchin donated to GOP presidential candidate Mitt Romney, he has a history of donating to Democratic candidates, which may raise red flags for conservatives.
He has donated to the following politicians, according to the Federal Election Commission: Bill Bradley in 2000, Hillary Clinton in 2000 and 2005, Al Gore in 2000, Kamala Harris in 2016, John Kerry in 2004, Barack Obama in 2004 and 2007 and Chuck Schumer in 1998.