9. Given that a line passing through the focus $F$ of the parabola $y^{2}=4 x$ intersects the parabola at points $M$ and $N$, and $E(m, 0)$ is a point on the $x$-axis. The extensions of $M E$ and $N E$ intersect the parabola at points $P$ and $Q$ respectively. If the slopes $k_{1}$ and $k_{2}$ of $M N$ and $P Q$ satisfy $k_{1}=3 k_{2}$, then the value of the real number $m$ is . $\qquad$
9.3.

When $M P$ is not perpendicular to the $x$-axis, let $l_{\text {MР }}: y=k(x-m)$.
Substitute into $y^{2}=4 x$ to get
$$
x^{2}-\left(\frac{4}{k^{2}}+2 m\right) x+m^{2}=0 \text {. }
$$

Then $x_{M} x_{P}=m^{2} \Rightarrow y_{M} y_{P}=-4 m$ $\Rightarrow y_{P}=\frac{-4 m}{y_{M}}$.
When $M P \perp x$-axis, the conclusion also holds.
Similarly, $y_{M} y_{N}=-4, y_{Q}=\frac{-4 m}{y_{N}}$.
Thus, $k_{1}=\frac{4}{y_{M}+y_{N}}, k_{2}=\frac{4}{y_{P}+y_{Q}}=\frac{1}{m} k_{1}$.
Also, $k_{2}=\frac{1}{3} k_{1}$, therefore, $m=3$.