# [Tex/LaTex] Italic style for subsection title, not for the number

formattingtitlesec

I'm trying to give to the subsection title an italic style, but I don't want that this style is applied also to the subsection number. Is it possible?

I'm trying in this way:

\documentclass{book}
\usepackage{titlesec}
\titleformat*{\subsection}{\normalsize\itshape}
\begin{document}

\tableofcontents

\chapter{Test}
\section{Test2}
\subsection{Test3}

\end{document}

but what I have is this:

As you can see also "1.1.1" is italic.