One of the most heartening stories in specialized diagnostics companies recently is CareDx. The company markets the AlloMap test for cardiac transplant rejection (where a blood test can sometimes replace a cardiac biopsy) and more recently the AlloSure test (screening for kidney transplant rejection by finding free circulating donor organ DNA in blood). Both are covered by the Medicare program, specifically, the Noridian/MolDx program. See an AlloSure publication, Bloom et al, 2017, here.
A year ago, on June 5, 2017, share price was $1.07. Today, June 8, 2018, it's $15.11, up fifteen times. This gives a market cap of $523M today, as opposed to about $16M last summer.
2015 revenue was $28M; by 2017 revenue rose to $48M. Quarterly revenue was up 17% from 2017Q2 to 2018Q1.
2017 net income was -$55M.
Other companies are also looking at the cfDNA & renal transplant space; see a UCSF/Natera collaboration announced in 2016 here.