“Because it is the most widely used illicit drug, marijuana is predictably the first illicit drug most people encounter [...] because underage smoking and alcohol use typically precede marijuana use, marijuana is not the most common and is rarely the first ‘gateway’ to illicit drug use. There is no conclusive evidence that the drug effects of marijuana are causally linked to the subsequent abuse of other illicit drugs.” [...] an alternative gateway may just be the trials and tribulations some kids face while growing up. “Whether marijuana smokers go on to use other illicit drugs depends more on social factors like being exposed to stress and being unemployed — not so much whether they smoked a joint in the eighth grade,”One in ten adults who regularly smoke the drug become dependent on it
Irrelevant to whether it's a gateway - and the proportion is higher for alcohol, btw.
and those who use it are more likely to go on to use harder drugs,
Still doesn't contradict what I posted above nor add up to a 'gateway' - most who use pot do not go on to use hard drugs.