  In this work we compare the predictions for the scattering length and
effective range of the channels $K^0 \Sigma^+, K^+ \Sigma^0 , K^+ \Lambda$ and
$\eta p$, assuming the $N^*(1535)$ state as a molecular state of these
channels, or an original genuine state, made for instance from three quarks.
Looking at very different scenarios, what we conclude is that the predictions
of these two pictures are drastically different, to the point that we advise
the measurement of these magnitudes, accessible for instance by measuring
correlation functions, in order to gain much valuable information concerning
the nature of this state.
