In order to emphasize text the command \emph can be used which usually displays the text in an italics font:
This is some text with \emph{emphasized words}.
The command \sout of the package ulem strikes through a text:
\sout{This text is striked through}
The package ulem redefines the command \emph. When you do not want to have this behavior you can use the package ulem with the option normalem:
\usepackage[normalem]{ulem}