Have researchers made significant inroads into the problem of AIDS?
Advanced English Dictionary
+noun ~ (into sth) something that is achieved, especially by reducing the power or success of sth else: This deal is their first major inroad into the American market. Idioms: make inroads into / on sth if one thing makes inroads into another, it has a noticeable effect on the second thing, especially by reducing it, or influencing it: Tax rises have made some inroads into the country's national debt. + By the 1950s, television had made great inroads into the territory of the news magazines.
Random quote: Silence is a true friend who never betrays.: Confucius