It's time to buy Adaptive Biotechnologies on its promising immune scan business, according to Piper Sandler. Analyst David Westenberg upgraded shares to overweight from neutral, saying they can nearly double from here on the company's minimal residual disease testing business. MRD can screen for blood cancer by getting a precise count of both malignant and health cells. "If the company can grow MRD revenue at 50% (as they expect and we model in 2023), we think the stock would deserve a ~10X revenue multiple on its MRD business," Westenberg wrote in a Wednesday note. "We're adjusting our estimates to slightly above consensus." The analyst expects the total addressable market for the minimal residual disease business could be in the "tens of billions," and he forecasts it will grow in the "high double digits" for the next five years. What's more, Adaptive Biotechnologies has a competitive position in the market. The analyst expects shares, which have plunged nearly 75% in 2022, can rebound next year on the strength of this growing business, as well as from its partnerships. The analyst's $14 price target, raised from $7.50, represents roughly 97% upside from Tuesday's closing price of $7.09. Shares jumped 13.5% on Wednesday. "At this point, we think the long term 'dream-the-dream' of an annual immune system scan represents a free call option," Westenberg wrote. "We understand that long duration/high terminal value assets are out-of-favor, but we like the valuation following a rough 2022 and the potential near term uptake of MRD," the analyst said. —CNBC's Michael Bloom contributed to this report.