* April retail sales rise 0.4 pct vs. est. 0.6 pct
* J.C. Penney drops on weak same-store sales
* Futures down: Dow 20 pts, S&P 3.25 pts, Nasdaq 2.25 pts (Adds details, comments, updates prices)
May 12 (Reuters) - U.S. stocks looked set to open slightly lower on Friday as investors assessed a raft of data to gauge the strength of the economy.
A Commerce Department report showed retail sales increased by 0.4 percent in April, but fell short of a 0.6 percent rise estimated by economists.
U.S. consumer prices rebounded in April, a Labor Department report showed, pointing to a steady rise in inflation that could make the case for an interest rate hike next month.
"Today, the focus is on macro news, while the political situation in Washington continues to linger. So we are looking at a cautious market," said Peter Cardillo, chief market economist at First Standard Financial in New York.
With the first-quarter earnings season coming to an end, investors are shifting their focus to central bank activity, economic data and developments in the Trump administration.
President Donald Trump unexpectedly fired his FBI chief on Tuesday, the potential fallout of which could delay his pursuit to cut taxes and boost spending.
Dow e-minis were down 20 points, or 0.1 percent at 8:35 a.m. ET (1235 GMT), with 20,069 contracts changing hands.
S&P 500 e-minis were down 3.25 points, or 0.14 percent, with 138,364 contracts traded.
Nasdaq 100 e-minis were down 2.25 points, or 0.04 percent, on volume of 22,448 contracts.
A selloff in the retail sector, sparked by Macy's weak results on Thursday, could continue after J.C. Penney reported lower-than-expected comparable store sales. The retailer's stock was down 5 percent in premarket trading.
CyberArk was down 10 percent at $49.52 after issuing a disappointing full-year earnings forecast.
Online advertising firm Trade Desk surged 22 percent to $48.80 after reporting quarterly revenue that handily beat analysts' estimates.
T-Mobile was up 3.3 percent at $68 after Bloomberg reported that Sprint and its controlling shareholder SoftBank have started talks to merge with T-Mobile US. Sprint shares rose 3.2 percent. (Reporting by Yashaswini Swamynathan in Bengaluru; Editing by Anil D'Silva)