Qualcomm on Monday announced it filed a suit against Apple, in response to the iPhone maker’s legal attacks from a few months ago. Apple alleged in its lawsuits that Qualcomm has been abusing it position in the chip industry to charge higher royalties on standard-essential patents and force Apple into exclusive deals. Apple also claimed that Qualcomm did not pay around $1 billion in licensing rebates.

Qualcomm responded to Apple’s claims, making several accusations of its own, and basically concluding that the massive iPhone success would not be possible without Qualcomm’s cellular chips.

The chipmaker has five key claims against Apple, alleging that Apple breached agreements and interfered in agreements with other licensees that manufacture iPhones and iPads for Apple.

Qualcomm also says Apple has encouraged regulatory attacks on Qualcomm in other jurisdictions. Qualcomm received two massive fines in China and South Korea in antitrust investigations and has to defend against a similar case brought forward by the FTC a few weeks before Apple sued Qualcomm.

Furthermore, Qualcomm also says that Apple chose not to utilize the full performance of Qualcomm’s modem chips in the iPhone 7, and misrepresented the performance disparity between the Qualcomm and Intel LTE chips in various iPhone 7 version. Furthermore, Qualcomm says that Apple threatened the company, to prevent it from making any public comparisons between the two competing LTE chips.

“Over the last ten years, Apple has played a significant role in bringing the benefits of mobile technology to consumers with its popular products and services,” Qualcomm executive vice president and general counsel Don Rosenberg said. “But Apple could not have built the incredible iPhone franchise that has made it the most profitable company in the world, capturing over 90 percent of smartphone profits, without relying upon Qualcomm’s fundamental cellular technologies.”

Qualcomm plans to “vigorously defend” its business model against Apple and seeks unspecified damages from the iPhone maker.