  Active region (AR) outflows have been studied in detail since the launch of
\textit{Hinode}/EIS and are believed to provide a possible source of mass and
energy to the slow solar wind. In this work, we investigate the lower
atmospheric counterpart of AR outflows using observations from the
\textit{Interface Region Imaging Spectrograph} (\textit{IRIS}). We find that
the \textit{IRIS} \siiv, \cii\ and \mgii\ transition region (TR) and
chromospheric lines exhibit different spectral features in the outflows as
compared to neighboring regions at the footpoints ("moss") of hot AR loops. The
average redshift of \siiv\ in the outflows region ($\approx$ 5.5~km s$^{-1}$)
is smaller than typical moss ($\approx$ 12--13 km~s$^{-1}$) and quiet Sun
($\approx$ 7.5 km~s$^{-1}$) values, while the \cii~line is blueshifted
($\approx$ -1.1--1.5 km~s$^{-1}$), in contrast to the moss where it is observed
to be redshifted by about $\approx$ 2.5 km~s$^{-1}$. Further, we observe that
the low atmosphere underneath the coronal outflows is highly structured, with
the presence of blueshifts in \siiv\ and positive \mgii\ k2 asymmetries (which
can be interpreted as signatures of chromospheric upflows) which are mostly not
observed in the moss. These observations show a clear correlation between the
coronal outflows and the chromosphere and TR underneath, which has not been
shown before. Our work strongly suggests that these regions are not separate
environments and should be treated together, and that current leading theories
of AR outflows, such as the interchange reconnection model, need to take into
account the dynamics of the low atmosphere.
