Hussain Chaudhry, 18, was fatally knifed as he and his family fought off a thug trying to steal a designer jacket yesterday evening outside their house in Leyton, East London.
It is believed the family run a home business selling clothing and the attack was launched after a customer arranged to visit the house.
The law student's mum and brother suffered slash wounds to their hands in the attack just after 5pm, neighbours said.
Hussain, a first-year student at SOAS University in London, was pronounced dead at the scene and police have launched a murder investigation.
His sister, Afia Ahmed Chaudhry, paid tribute to her younger brother on Twitter, writing: "We've lost our baby and no pain will compare".
She said: "The sunshine of my life. My youngest brother, Hussain.

Heartbroken sister of teen, 18, knifed defending mum pays tribute to 'our baby'
THE heartbroken sister of a teenager who died in his mum’s arms after being stabbed in the neck defending his family from a robber has paid tribute to “our baby”. Hussain Chaudhry…

Likely down to an issue of religion. I wish this kind of thing didn't happen.