You might think the home button is an indispensable feature of any iPhone; a port in the storm whenever you're caught between apps, your device is on standby or Safari is playing up.
But not so, it seems, as reports suggest its days could be numbered. Apple is believed to be working on technology that will render the home button redundant and eventually see it disappear from your handsets.
Not just yet perhaps, but certainly in the years to come. Scary stuff for many iPhone users.
For a while, it seemed the addition of a Touch ID fingerprint scanner had only heightened the importance of the home button, by giving it additional security functionality.
But Digitimes doesn't seem to think so. The Taiwan-based news provider says Apple is developing touch and display driver integration single-chip solutions for its iPhones, which will come with integrated fingerprint sensors.
This would allow the Touch ID function to move onto the smartphone screen, paving the way for a virtual home button and, crucially, a larger iPhone display.
With Apple rumoured to be lining up Force Touch technology for the iPhone 6S - as featured on the Apple Watch and most recent MacBooks - all this starts to make sense.
The Digitimes report has been backed up by AppleInsider, which cites its own source as saying a radical iPhone redesign is on the way, albeit not for at least another two years.
None of this is guaranteed mind. The informer hedged his bets somewhat, claiming that although Apple's long-term aim is to ditch the home button, technical challenges lie ahead.
It isn't unfeasible the effort could be scrapped entirely, or another innovation may come along to provide an alternative.
Then of course, there's the customer factor. It remains to be seen how iPhone users will respond to rumours of a radical design overhaul.
Remember the outcry when the Start menu was ditched for Windows 8? Microsoft might just wish it had conceded defeat on that particular battle at the outset.
For some iPhone users, sacrificing an inch of screen size seems a small price to pay for the safety, security and simplicity of the home button. Yet those with a greater sense of adventure may welcome a larger display and touch-sensitive controls.
Apple has plenty to consider over the coming months. Once the technology catches up with the vision, it will have a big decision to make.