You have them, your mum has them, your best mate has them, that girl sitting across the desk from you has them and Chrissy Teigen has them.
Whether it's a sudden growth spurt as a teen, those things called 'boobs' or a pregnancy, there are numerous bodily changes create stretch marks - or rather, 'glitter stripes' as a 'body-positive' Instagram user recently called them.
And one guy who can't get enough of our 'lady lines' is rapper Kendrick Lamar, who is celebrating our natural figures – scars and all – in his latest video for his single, Humble.
In the video, the 29-year-old raps:
I'm so f*ckin' sick and tired of the Photoshop/
Show me somethin' natural like afro on Richard Pryor/
Show me somethin' natural like ass with some stretchmarks/
Still will take you down right on your mama's couch in Polo socks, ayy/
In the clip, Lamar stands next to a girl with slicked back hair, make-up and a figure-hugging top.
In the next frame the model is seen with her hair loose, wearing a tank top and without a smidge of make-up on her face, before a woman wearing black pants shakes her bum, proudly showing off her stretch marks.
Unsurprisingly, Lamar's celebration of stretch marks has garnered praise among women (and men) on Twitter who have endured years of the scarring being deemed ugly or to be covered.
Wear those stretch marks with pride, ladies.