[Tex/LaTex] Italicizing of amsthm package

Question

I'm using the amsthm package, and I noticed that a remark is automatically italicized, while a theorem and a proposition are not.

What other keywords have their content automatically italicized by the package?

Edit: I did not define any theorem styles. I simply used

\newtheorem{theorem}{Theorem}
\newtheorem{proposition}[theorem]{Proposition}
\newtheorem{remark}[theorem]{Remark}

Answer 1

It is set by \theoremstyle{#1}. The possible values are plain, definition and remark. E.g.

\documentclass{article}
\usepackage{amsthm}

\theoremstyle{plain}% default
\newtheorem{thm}{Theorem}[section]
\newtheorem{lem}[thm]{Lemma}
\newtheorem{prop}[thm]{Proposition}


\theoremstyle{definition}
\newtheorem{defn}{Definition}[section]
\newtheorem{exmp}{Example}[section]


\theoremstyle{remark}
\newtheorem{rem}{Remark}


\begin{document}

\section{First}

\begin{thm}
One plus one equals two.
\end{thm}

\begin{lem}
One plus one equals two.
\end{lem}

\begin{prop}
One plus one equals two.
\end{prop}


\begin{defn}
Two is one plus one.
\end{defn}

\begin{rem}
One plus one equals two.
\end{rem}


\end{document}